1 /*
2 * Copyright (c) 1997, 2026, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2024, 2025, Alibaba Group Holding Limited. All rights reserved.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26 #include "gc/shared/barrierSet.hpp"
27 #include "gc/shared/c2/barrierSetC2.hpp"
28 #include "libadt/vectset.hpp"
29 #include "memory/allocation.inline.hpp"
30 #include "memory/resourceArea.hpp"
31 #include "opto/ad.hpp"
32 #include "opto/callGenerator.hpp"
33 #include "opto/castnode.hpp"
34 #include "opto/cfgnode.hpp"
35 #include "opto/connode.hpp"
36 #include "opto/loopnode.hpp"
37 #include "opto/machnode.hpp"
38 #include "opto/matcher.hpp"
39 #include "opto/node.hpp"
40 #include "opto/opcodes.hpp"
41 #include "opto/reachability.hpp"
42 #include "opto/regmask.hpp"
43 #include "opto/rootnode.hpp"
44 #include "opto/type.hpp"
45 #include "utilities/copy.hpp"
46 #include "utilities/macros.hpp"
47 #include "utilities/powerOfTwo.hpp"
48 #include "utilities/stringUtils.hpp"
49
50 class RegMask;
51 // #include "phase.hpp"
52 class PhaseTransform;
53 class PhaseGVN;
54
55 // Arena we are currently building Nodes in
56 const uint Node::NotAMachineReg = 0xffff0000;
57
58 #ifndef PRODUCT
59 extern uint nodes_created;
60 #endif
61 #ifdef __clang__
62 #pragma clang diagnostic push
63 #pragma GCC diagnostic ignored "-Wuninitialized"
64 #endif
65
66 #ifdef ASSERT
67
68 //-------------------------- construct_node------------------------------------
69 // Set a breakpoint here to identify where a particular node index is built.
70 void Node::verify_construction() {
71 _debug_orig = nullptr;
72 // The decimal digits of _debug_idx are <compile_id> followed by 10 digits of <_idx>
73 Compile* C = Compile::current();
74 assert(C->unique() < (INT_MAX - 1), "Node limit exceeded INT_MAX");
75 uint64_t new_debug_idx = (uint64_t)C->compile_id() * 10000000000 + _idx;
76 set_debug_idx(new_debug_idx);
77 if (!C->phase_optimize_finished()) {
78 // Only check assert during parsing and optimization phase. Skip it while generating code.
79 assert(C->live_nodes() <= C->max_node_limit(), "Live Node limit exceeded limit");
80 }
81 if (BreakAtNode != 0 && (_debug_idx == BreakAtNode || (uint64_t)_idx == BreakAtNode)) {
82 tty->print_cr("BreakAtNode: _idx=%d _debug_idx=" UINT64_FORMAT, _idx, _debug_idx);
83 BREAKPOINT;
84 }
85 #if OPTO_DU_ITERATOR_ASSERT
86 _last_del = nullptr;
87 _del_tick = 0;
88 #endif
89 _hash_lock = 0;
90 }
91
92
93 // #ifdef ASSERT ...
94
95 #if OPTO_DU_ITERATOR_ASSERT
96 void DUIterator_Common::sample(const Node* node) {
97 _vdui = VerifyDUIterators;
98 _node = node;
99 _outcnt = node->_outcnt;
100 _del_tick = node->_del_tick;
101 _last = nullptr;
102 }
103
104 void DUIterator_Common::verify(const Node* node, bool at_end_ok) {
105 assert(_node == node, "consistent iterator source");
106 assert(_del_tick == node->_del_tick, "no unexpected deletions allowed");
107 }
108
109 void DUIterator_Common::verify_resync() {
110 // Ensure that the loop body has just deleted the last guy produced.
111 const Node* node = _node;
112 // Ensure that at least one copy of the last-seen edge was deleted.
113 // Note: It is OK to delete multiple copies of the last-seen edge.
114 // Unfortunately, we have no way to verify that all the deletions delete
115 // that same edge. On this point we must use the Honor System.
116 assert(node->_del_tick >= _del_tick+1, "must have deleted an edge");
117 assert(node->_last_del == _last, "must have deleted the edge just produced");
118 // We liked this deletion, so accept the resulting outcnt and tick.
119 _outcnt = node->_outcnt;
120 _del_tick = node->_del_tick;
121 }
122
123 void DUIterator_Common::reset(const DUIterator_Common& that) {
124 if (this == &that) return; // ignore assignment to self
125 if (!_vdui) {
126 // We need to initialize everything, overwriting garbage values.
127 _last = that._last;
128 _vdui = that._vdui;
129 }
130 // Note: It is legal (though odd) for an iterator over some node x
131 // to be reassigned to iterate over another node y. Some doubly-nested
132 // progress loops depend on being able to do this.
133 const Node* node = that._node;
134 // Re-initialize everything, except _last.
135 _node = node;
136 _outcnt = node->_outcnt;
137 _del_tick = node->_del_tick;
138 }
139
140 void DUIterator::sample(const Node* node) {
141 DUIterator_Common::sample(node); // Initialize the assertion data.
142 _refresh_tick = 0; // No refreshes have happened, as yet.
143 }
144
145 void DUIterator::verify(const Node* node, bool at_end_ok) {
146 DUIterator_Common::verify(node, at_end_ok);
147 assert(_idx < node->_outcnt + (uint)at_end_ok, "idx in range");
148 }
149
150 void DUIterator::verify_increment() {
151 if (_refresh_tick & 1) {
152 // We have refreshed the index during this loop.
153 // Fix up _idx to meet asserts.
154 if (_idx > _outcnt) _idx = _outcnt;
155 }
156 verify(_node, true);
157 }
158
159 void DUIterator::verify_resync() {
160 // Note: We do not assert on _outcnt, because insertions are OK here.
161 DUIterator_Common::verify_resync();
162 // Make sure we are still in sync, possibly with no more out-edges:
163 verify(_node, true);
164 }
165
166 void DUIterator::reset(const DUIterator& that) {
167 if (this == &that) return; // self assignment is always a no-op
168 assert(that._refresh_tick == 0, "assign only the result of Node::outs()");
169 assert(that._idx == 0, "assign only the result of Node::outs()");
170 assert(_idx == that._idx, "already assigned _idx");
171 if (!_vdui) {
172 // We need to initialize everything, overwriting garbage values.
173 sample(that._node);
174 } else {
175 DUIterator_Common::reset(that);
176 if (_refresh_tick & 1) {
177 _refresh_tick++; // Clear the "was refreshed" flag.
178 }
179 assert(_refresh_tick < 2*100000, "DU iteration must converge quickly");
180 }
181 }
182
183 void DUIterator::refresh() {
184 DUIterator_Common::sample(_node); // Re-fetch assertion data.
185 _refresh_tick |= 1; // Set the "was refreshed" flag.
186 }
187
188 void DUIterator::verify_finish() {
189 // If the loop has killed the node, do not require it to re-run.
190 if (_node->_outcnt == 0) _refresh_tick &= ~1;
191 // If this assert triggers, it means that a loop used refresh_out_pos
192 // to re-synch an iteration index, but the loop did not correctly
193 // re-run itself, using a "while (progress)" construct.
194 // This iterator enforces the rule that you must keep trying the loop
195 // until it "runs clean" without any need for refreshing.
196 assert(!(_refresh_tick & 1), "the loop must run once with no refreshing");
197 }
198
199
200 void DUIterator_Fast::verify(const Node* node, bool at_end_ok) {
201 DUIterator_Common::verify(node, at_end_ok);
202 Node** out = node->_out;
203 uint cnt = node->_outcnt;
204 assert(cnt == _outcnt, "no insertions allowed");
205 assert(_outp >= out && _outp <= out + cnt - !at_end_ok, "outp in range");
206 // This last check is carefully designed to work for NO_OUT_ARRAY.
207 }
208
209 void DUIterator_Fast::verify_limit() {
210 const Node* node = _node;
211 verify(node, true);
212 assert(_outp == node->_out + node->_outcnt, "limit still correct");
213 }
214
215 void DUIterator_Fast::verify_resync() {
216 const Node* node = _node;
217 if (_outp == node->_out + _outcnt) {
218 // Note that the limit imax, not the pointer i, gets updated with the
219 // exact count of deletions. (For the pointer it's always "--i".)
220 assert(node->_outcnt+node->_del_tick == _outcnt+_del_tick, "no insertions allowed with deletion(s)");
221 // This is a limit pointer, with a name like "imax".
222 // Fudge the _last field so that the common assert will be happy.
223 _last = (Node*) node->_last_del;
224 DUIterator_Common::verify_resync();
225 } else {
226 assert(node->_outcnt < _outcnt, "no insertions allowed with deletion(s)");
227 // A normal internal pointer.
228 DUIterator_Common::verify_resync();
229 // Make sure we are still in sync, possibly with no more out-edges:
230 verify(node, true);
231 }
232 }
233
234 void DUIterator_Fast::verify_relimit(uint n) {
235 const Node* node = _node;
236 assert((int)n > 0, "use imax -= n only with a positive count");
237 // This must be a limit pointer, with a name like "imax".
238 assert(_outp == node->_out + node->_outcnt, "apply -= only to a limit (imax)");
239 // The reported number of deletions must match what the node saw.
240 assert(node->_del_tick == _del_tick + n, "must have deleted n edges");
241 // Fudge the _last field so that the common assert will be happy.
242 _last = (Node*) node->_last_del;
243 DUIterator_Common::verify_resync();
244 }
245
246 void DUIterator_Fast::reset(const DUIterator_Fast& that) {
247 assert(_outp == that._outp, "already assigned _outp");
248 DUIterator_Common::reset(that);
249 }
250
251 void DUIterator_Last::verify(const Node* node, bool at_end_ok) {
252 // at_end_ok means the _outp is allowed to underflow by 1
253 _outp += at_end_ok;
254 DUIterator_Fast::verify(node, at_end_ok); // check _del_tick, etc.
255 _outp -= at_end_ok;
256 assert(_outp == (node->_out + node->_outcnt) - 1, "pointer must point to end of nodes");
257 }
258
259 void DUIterator_Last::verify_limit() {
260 // Do not require the limit address to be resynched.
261 //verify(node, true);
262 assert(_outp == _node->_out, "limit still correct");
263 }
264
265 void DUIterator_Last::verify_step(uint num_edges) {
266 assert((int)num_edges > 0, "need non-zero edge count for loop progress");
267 _outcnt -= num_edges;
268 _del_tick += num_edges;
269 // Make sure we are still in sync, possibly with no more out-edges:
270 const Node* node = _node;
271 verify(node, true);
272 assert(node->_last_del == _last, "must have deleted the edge just produced");
273 }
274
275 #endif //OPTO_DU_ITERATOR_ASSERT
276
277
278 #endif //ASSERT
279
280
281 // This constant used to initialize _out may be any non-null value.
282 // The value null is reserved for the top node only.
283 #define NO_OUT_ARRAY ((Node**)-1)
284
285 // Out-of-line code from node constructors.
286 // Executed only when extra debug info. is being passed around.
287 static void init_node_notes(Compile* C, int idx, Node_Notes* nn) {
288 C->set_node_notes_at(idx, nn);
289 }
290
291 // Shared initialization code.
292 inline int Node::Init(int req) {
293 Compile* C = Compile::current();
294 int idx = C->next_unique();
295 NOT_PRODUCT(_igv_idx = C->next_igv_idx());
296
297 // Allocate memory for the necessary number of edges.
298 if (req > 0) {
299 // Allocate space for _in array to have double alignment.
300 _in = (Node **) ((char *) (C->node_arena()->AmallocWords(req * sizeof(void*))));
301 }
302 // If there are default notes floating around, capture them:
303 Node_Notes* nn = C->default_node_notes();
304 if (nn != nullptr) init_node_notes(C, idx, nn);
305
306 // Note: At this point, C is dead,
307 // and we begin to initialize the new Node.
308
309 _cnt = _max = req;
310 _outcnt = _outmax = 0;
311 _class_id = Class_Node;
312 _flags = 0;
313 _out = NO_OUT_ARRAY;
314 return idx;
315 }
316
317 //------------------------------Node-------------------------------------------
318 // Create a Node, with a given number of required edges.
319 Node::Node(uint req)
320 : _idx(Init(req))
321 #ifdef ASSERT
322 , _parse_idx(_idx)
323 #endif
324 {
325 assert( req < Compile::current()->max_node_limit() - NodeLimitFudgeFactor, "Input limit exceeded" );
326 DEBUG_ONLY( verify_construction() );
327 NOT_PRODUCT(nodes_created++);
328 if (req == 0) {
329 _in = nullptr;
330 } else {
331 Node** to = _in;
332 for(uint i = 0; i < req; i++) {
333 to[i] = nullptr;
334 }
335 }
336 }
337
338 //------------------------------Node-------------------------------------------
339 Node::Node(Node *n0)
340 : _idx(Init(1))
341 #ifdef ASSERT
342 , _parse_idx(_idx)
343 #endif
344 {
345 DEBUG_ONLY( verify_construction() );
346 NOT_PRODUCT(nodes_created++);
347 assert( is_not_dead(n0), "can not use dead node");
348 _in[0] = n0; if (n0 != nullptr) n0->add_out((Node *)this);
349 }
350
351 //------------------------------Node-------------------------------------------
352 Node::Node(Node *n0, Node *n1)
353 : _idx(Init(2))
354 #ifdef ASSERT
355 , _parse_idx(_idx)
356 #endif
357 {
358 DEBUG_ONLY( verify_construction() );
359 NOT_PRODUCT(nodes_created++);
360 assert( is_not_dead(n0), "can not use dead node");
361 assert( is_not_dead(n1), "can not use dead node");
362 _in[0] = n0; if (n0 != nullptr) n0->add_out((Node *)this);
363 _in[1] = n1; if (n1 != nullptr) n1->add_out((Node *)this);
364 }
365
366 //------------------------------Node-------------------------------------------
367 Node::Node(Node *n0, Node *n1, Node *n2)
368 : _idx(Init(3))
369 #ifdef ASSERT
370 , _parse_idx(_idx)
371 #endif
372 {
373 DEBUG_ONLY( verify_construction() );
374 NOT_PRODUCT(nodes_created++);
375 assert( is_not_dead(n0), "can not use dead node");
376 assert( is_not_dead(n1), "can not use dead node");
377 assert( is_not_dead(n2), "can not use dead node");
378 _in[0] = n0; if (n0 != nullptr) n0->add_out((Node *)this);
379 _in[1] = n1; if (n1 != nullptr) n1->add_out((Node *)this);
380 _in[2] = n2; if (n2 != nullptr) n2->add_out((Node *)this);
381 }
382
383 //------------------------------Node-------------------------------------------
384 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3)
385 : _idx(Init(4))
386 #ifdef ASSERT
387 , _parse_idx(_idx)
388 #endif
389 {
390 DEBUG_ONLY( verify_construction() );
391 NOT_PRODUCT(nodes_created++);
392 assert( is_not_dead(n0), "can not use dead node");
393 assert( is_not_dead(n1), "can not use dead node");
394 assert( is_not_dead(n2), "can not use dead node");
395 assert( is_not_dead(n3), "can not use dead node");
396 _in[0] = n0; if (n0 != nullptr) n0->add_out((Node *)this);
397 _in[1] = n1; if (n1 != nullptr) n1->add_out((Node *)this);
398 _in[2] = n2; if (n2 != nullptr) n2->add_out((Node *)this);
399 _in[3] = n3; if (n3 != nullptr) n3->add_out((Node *)this);
400 }
401
402 //------------------------------Node-------------------------------------------
403 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3, Node *n4)
404 : _idx(Init(5))
405 #ifdef ASSERT
406 , _parse_idx(_idx)
407 #endif
408 {
409 DEBUG_ONLY( verify_construction() );
410 NOT_PRODUCT(nodes_created++);
411 assert( is_not_dead(n0), "can not use dead node");
412 assert( is_not_dead(n1), "can not use dead node");
413 assert( is_not_dead(n2), "can not use dead node");
414 assert( is_not_dead(n3), "can not use dead node");
415 assert( is_not_dead(n4), "can not use dead node");
416 _in[0] = n0; if (n0 != nullptr) n0->add_out((Node *)this);
417 _in[1] = n1; if (n1 != nullptr) n1->add_out((Node *)this);
418 _in[2] = n2; if (n2 != nullptr) n2->add_out((Node *)this);
419 _in[3] = n3; if (n3 != nullptr) n3->add_out((Node *)this);
420 _in[4] = n4; if (n4 != nullptr) n4->add_out((Node *)this);
421 }
422
423 //------------------------------Node-------------------------------------------
424 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
425 Node *n4, Node *n5)
426 : _idx(Init(6))
427 #ifdef ASSERT
428 , _parse_idx(_idx)
429 #endif
430 {
431 DEBUG_ONLY( verify_construction() );
432 NOT_PRODUCT(nodes_created++);
433 assert( is_not_dead(n0), "can not use dead node");
434 assert( is_not_dead(n1), "can not use dead node");
435 assert( is_not_dead(n2), "can not use dead node");
436 assert( is_not_dead(n3), "can not use dead node");
437 assert( is_not_dead(n4), "can not use dead node");
438 assert( is_not_dead(n5), "can not use dead node");
439 _in[0] = n0; if (n0 != nullptr) n0->add_out((Node *)this);
440 _in[1] = n1; if (n1 != nullptr) n1->add_out((Node *)this);
441 _in[2] = n2; if (n2 != nullptr) n2->add_out((Node *)this);
442 _in[3] = n3; if (n3 != nullptr) n3->add_out((Node *)this);
443 _in[4] = n4; if (n4 != nullptr) n4->add_out((Node *)this);
444 _in[5] = n5; if (n5 != nullptr) n5->add_out((Node *)this);
445 }
446
447 //------------------------------Node-------------------------------------------
448 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
449 Node *n4, Node *n5, Node *n6)
450 : _idx(Init(7))
451 #ifdef ASSERT
452 , _parse_idx(_idx)
453 #endif
454 {
455 DEBUG_ONLY( verify_construction() );
456 NOT_PRODUCT(nodes_created++);
457 assert( is_not_dead(n0), "can not use dead node");
458 assert( is_not_dead(n1), "can not use dead node");
459 assert( is_not_dead(n2), "can not use dead node");
460 assert( is_not_dead(n3), "can not use dead node");
461 assert( is_not_dead(n4), "can not use dead node");
462 assert( is_not_dead(n5), "can not use dead node");
463 assert( is_not_dead(n6), "can not use dead node");
464 _in[0] = n0; if (n0 != nullptr) n0->add_out((Node *)this);
465 _in[1] = n1; if (n1 != nullptr) n1->add_out((Node *)this);
466 _in[2] = n2; if (n2 != nullptr) n2->add_out((Node *)this);
467 _in[3] = n3; if (n3 != nullptr) n3->add_out((Node *)this);
468 _in[4] = n4; if (n4 != nullptr) n4->add_out((Node *)this);
469 _in[5] = n5; if (n5 != nullptr) n5->add_out((Node *)this);
470 _in[6] = n6; if (n6 != nullptr) n6->add_out((Node *)this);
471 }
472
473 #ifdef __clang__
474 #pragma clang diagnostic pop
475 #endif
476
477
478 //------------------------------clone------------------------------------------
479 // Clone a Node.
480 Node *Node::clone() const {
481 Compile* C = Compile::current();
482 uint s = size_of(); // Size of inherited Node
483 Node *n = (Node*)C->node_arena()->AmallocWords(size_of() + _max*sizeof(Node*));
484 Copy::conjoint_words_to_lower((HeapWord*)this, (HeapWord*)n, s);
485 // Set the new input pointer array
486 n->_in = (Node**)(((char*)n)+s);
487 // Cannot share the old output pointer array, so kill it
488 n->_out = NO_OUT_ARRAY;
489 // And reset the counters to 0
490 n->_outcnt = 0;
491 n->_outmax = 0;
492 // Unlock this guy, since he is not in any hash table.
493 DEBUG_ONLY(n->_hash_lock = 0);
494 // Walk the old node's input list to duplicate its edges
495 uint i;
496 for( i = 0; i < len(); i++ ) {
497 Node *x = in(i);
498 n->_in[i] = x;
499 if (x != nullptr) x->add_out(n);
500 }
501 if (is_macro()) {
502 C->add_macro_node(n);
503 }
504 if (is_expensive()) {
505 C->add_expensive_node(n);
506 }
507 if (is_ReachabilityFence()) {
508 C->add_reachability_fence(n->as_ReachabilityFence());
509 }
510 if (for_post_loop_opts_igvn()) {
511 // Don't add cloned node to Compile::_for_post_loop_opts_igvn list automatically.
512 // If it is applicable, it will happen anyway when the cloned node is registered with IGVN.
513 n->remove_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
514 }
515 if (for_merge_stores_igvn()) {
516 // Don't add cloned node to Compile::_for_merge_stores_igvn list automatically.
517 // If it is applicable, it will happen anyway when the cloned node is registered with IGVN.
518 n->remove_flag(Node::NodeFlags::Flag_for_merge_stores_igvn);
519 }
520 if (n->is_ParsePredicate()) {
521 C->add_parse_predicate(n->as_ParsePredicate());
522 }
523 if (n->is_OpaqueTemplateAssertionPredicate()) {
524 C->add_template_assertion_predicate_opaque(n->as_OpaqueTemplateAssertionPredicate());
525 }
526
527 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
528 bs->register_potential_barrier_node(n);
529
530 n->set_idx(C->next_unique()); // Get new unique index as well
531 NOT_PRODUCT(n->_igv_idx = C->next_igv_idx());
532 DEBUG_ONLY( n->verify_construction() );
533 NOT_PRODUCT(nodes_created++);
534 // Do not patch over the debug_idx of a clone, because it makes it
535 // impossible to break on the clone's moment of creation.
536 //DEBUG_ONLY( n->set_debug_idx( debug_idx() ) );
537
538 C->copy_node_notes_to(n, (Node*) this);
539
540 // MachNode clone
541 uint nopnds;
542 if (this->is_Mach() && (nopnds = this->as_Mach()->num_opnds()) > 0) {
543 MachNode *mach = n->as_Mach();
544 MachNode *mthis = this->as_Mach();
545 // Get address of _opnd_array.
546 // It should be the same offset since it is the clone of this node.
547 MachOper **from = mthis->_opnds;
548 MachOper **to = (MachOper **)((size_t)(&mach->_opnds) +
549 pointer_delta((const void*)from,
550 (const void*)(&mthis->_opnds), 1));
551 mach->_opnds = to;
552 for ( uint i = 0; i < nopnds; ++i ) {
553 to[i] = from[i]->clone();
554 }
555 }
556 if (this->is_MachProj()) {
557 // MachProjNodes contain register masks that may contain pointers to
558 // externally allocated memory. Make sure to use a proper constructor
559 // instead of just shallowly copying.
560 MachProjNode* mach = n->as_MachProj();
561 MachProjNode* mthis = this->as_MachProj();
562 new (&mach->_rout) RegMask(mthis->_rout);
563 }
564 if (n->is_Call()) {
565 // CallGenerator is linked to the original node.
566 CallGenerator* cg = n->as_Call()->generator();
567 if (cg != nullptr) {
568 CallGenerator* cloned_cg = cg->with_call_node(n->as_Call());
569 n->as_Call()->set_generator(cloned_cg);
570 }
571 }
572 if (n->is_SafePoint()) {
573 // Scalar replacement and macro expansion might modify the JVMState.
574 // Clone it to make sure it's not shared between SafePointNodes.
575 n->as_SafePoint()->clone_jvms(C);
576 n->as_SafePoint()->clone_replaced_nodes();
577 }
578 Compile::current()->record_modified_node(n);
579 return n; // Return the clone
580 }
581
582 //---------------------------setup_is_top--------------------------------------
583 // Call this when changing the top node, to reassert the invariants
584 // required by Node::is_top. See Compile::set_cached_top_node.
585 void Node::setup_is_top() {
586 if (this == (Node*)Compile::current()->top()) {
587 // This node has just become top. Kill its out array.
588 _outcnt = _outmax = 0;
589 _out = nullptr; // marker value for top
590 assert(is_top(), "must be top");
591 } else {
592 if (_out == nullptr) _out = NO_OUT_ARRAY;
593 assert(!is_top(), "must not be top");
594 }
595 }
596
597 //------------------------------~Node------------------------------------------
598 // Fancy destructor; eagerly attempt to reclaim Node numberings and storage
599 void Node::destruct(PhaseValues* phase) {
600 assert(this != Compile::current()->dead_path(), "we want to keep the unique DeadPath node around");
601 Compile* compile = (phase != nullptr) ? phase->C : Compile::current();
602 if (phase != nullptr && phase->is_IterGVN()) {
603 phase->is_IterGVN()->_worklist.remove(this);
604 }
605 // If this is the most recently created node, reclaim its index. Otherwise,
606 // record the node as dead to keep liveness information accurate.
607 if ((uint)_idx+1 == compile->unique()) {
608 compile->set_unique(compile->unique()-1);
609 } else {
610 compile->record_dead_node(_idx);
611 }
612 // Clear debug info:
613 Node_Notes* nn = compile->node_notes_at(_idx);
614 if (nn != nullptr) nn->clear();
615 // Walk the input array, freeing the corresponding output edges
616 _cnt = _max; // forget req/prec distinction
617 uint i;
618 for( i = 0; i < _max; i++ ) {
619 set_req(i, nullptr);
620 //assert(def->out(def->outcnt()-1) == (Node *)this,"bad def-use hacking in reclaim");
621 }
622 assert(outcnt() == 0, "deleting a node must not leave a dangling use");
623
624 if (is_macro()) {
625 compile->remove_macro_node(this);
626 }
627 if (is_expensive()) {
628 compile->remove_expensive_node(this);
629 }
630 if (is_ReachabilityFence()) {
631 compile->remove_reachability_fence(as_ReachabilityFence());
632 }
633 if (is_OpaqueTemplateAssertionPredicate()) {
634 compile->remove_template_assertion_predicate_opaque(as_OpaqueTemplateAssertionPredicate());
635 }
636 if (is_ParsePredicate()) {
637 compile->remove_parse_predicate(as_ParsePredicate());
638 }
639 if (for_post_loop_opts_igvn()) {
640 compile->remove_from_post_loop_opts_igvn(this);
641 }
642 if (for_merge_stores_igvn()) {
643 compile->remove_from_merge_stores_igvn(this);
644 }
645
646 if (is_SafePoint()) {
647 as_SafePoint()->delete_replaced_nodes();
648
649 if (is_CallStaticJava()) {
650 compile->remove_unstable_if_trap(as_CallStaticJava(), false);
651 }
652 }
653 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
654 bs->unregister_potential_barrier_node(this);
655
656 // See if the input array was allocated just prior to the object
657 int edge_size = _max*sizeof(void*);
658 int out_edge_size = _outmax*sizeof(void*);
659 char *in_array = ((char*)_in);
660 char *edge_end = in_array + edge_size;
661 char *out_array = (char*)(_out == NO_OUT_ARRAY? nullptr: _out);
662 int node_size = size_of();
663
664 #ifdef ASSERT
665 // We will not actually delete the storage, but we'll make the node unusable.
666 compile->remove_modified_node(this);
667 *(address*)this = badAddress; // smash the C++ vtbl, probably
668 _in = _out = (Node**) badAddress;
669 _max = _cnt = _outmax = _outcnt = 0;
670 #endif
671
672 // Free the output edge array
673 if (out_edge_size > 0) {
674 compile->node_arena()->Afree(out_array, out_edge_size);
675 }
676
677 // Free the input edge array and the node itself
678 if( edge_end == (char*)this ) {
679 // It was; free the input array and object all in one hit
680 #ifndef ASSERT
681 compile->node_arena()->Afree(in_array, edge_size+node_size);
682 #endif
683 } else {
684 // Free just the input array
685 compile->node_arena()->Afree(in_array, edge_size);
686
687 // Free just the object
688 #ifndef ASSERT
689 compile->node_arena()->Afree(this, node_size);
690 #endif
691 }
692 }
693
694 // Resize input or output array to grow it to the next larger power-of-2 bigger
695 // than len.
696 void Node::resize_array(Node**& array, node_idx_t& max_size, uint len, bool needs_clearing) {
697 Arena* arena = Compile::current()->node_arena();
698 uint new_max = max_size;
699 if (new_max == 0) {
700 max_size = 4;
701 array = (Node**)arena->Amalloc(4 * sizeof(Node*));
702 if (needs_clearing) {
703 array[0] = nullptr;
704 array[1] = nullptr;
705 array[2] = nullptr;
706 array[3] = nullptr;
707 }
708 return;
709 }
710 new_max = next_power_of_2(len);
711 assert(needs_clearing || (array != nullptr && array != NO_OUT_ARRAY), "out must have sensible value");
712 array = (Node**)arena->Arealloc(array, max_size * sizeof(Node*), new_max * sizeof(Node*));
713 if (needs_clearing) {
714 Copy::zero_to_bytes(&array[max_size], (new_max - max_size) * sizeof(Node*)); // null all new space
715 }
716 max_size = new_max; // Record new max length
717 // This assertion makes sure that Node::_max is wide enough to
718 // represent the numerical value of new_max.
719 assert(max_size > len, "int width of _max or _outmax is too small");
720 }
721
722 //------------------------------grow-------------------------------------------
723 // Grow the input array, making space for more edges
724 void Node::grow(uint len) {
725 resize_array(_in, _max, len, true);
726 }
727
728 //-----------------------------out_grow----------------------------------------
729 // Grow the input array, making space for more edges
730 void Node::out_grow(uint len) {
731 assert(!is_top(), "cannot grow a top node's out array");
732 resize_array(_out, _outmax, len, false);
733 }
734
735 #ifdef ASSERT
736 //------------------------------is_dead----------------------------------------
737 bool Node::is_dead() const {
738 // Mach and pinch point nodes may look like dead.
739 if (is_top() || is_Mach() || (Opcode() == Op_Node && _outcnt > 0) || this == Compile::current()->dead_path()) {
740 return false;
741 }
742 for (uint i = 0; i < _max; i++) {
743 if (_in[i] != nullptr) {
744 return false;
745 }
746 }
747 return true;
748 }
749
750 bool Node::is_not_dead(const Node* n) {
751 return n == nullptr || !PhaseIterGVN::is_verify_def_use() || !(n->is_dead());
752 }
753
754 bool Node::is_reachable_from_root() const {
755 ResourceMark rm;
756 Unique_Node_List wq;
757 wq.push((Node*)this);
758 RootNode* root = Compile::current()->root();
759 for (uint i = 0; i < wq.size(); i++) {
760 Node* m = wq.at(i);
761 if (m == root) {
762 return true;
763 }
764 for (DUIterator_Fast jmax, j = m->fast_outs(jmax); j < jmax; j++) {
765 Node* u = m->fast_out(j);
766 wq.push(u);
767 }
768 }
769 return false;
770 }
771 #endif
772
773 //------------------------------is_unreachable---------------------------------
774 bool Node::is_unreachable(PhaseIterGVN &igvn) const {
775 assert(!is_Mach(), "doesn't work with MachNodes");
776 return outcnt() == 0 || igvn.type(this) == Type::TOP || (in(0) != nullptr && in(0)->is_top());
777 }
778
779 //------------------------------add_req----------------------------------------
780 // Add a new required input at the end
781 void Node::add_req( Node *n ) {
782 assert( is_not_dead(n), "can not use dead node");
783
784 // Look to see if I can move precedence down one without reallocating
785 if( (_cnt >= _max) || (in(_max-1) != nullptr) )
786 grow( _max+1 );
787
788 // Find a precedence edge to move
789 if( in(_cnt) != nullptr ) { // Next precedence edge is busy?
790 uint i;
791 for( i=_cnt; i<_max; i++ )
792 if( in(i) == nullptr ) // Find the null at end of prec edge list
793 break; // There must be one, since we grew the array
794 _in[i] = in(_cnt); // Move prec over, making space for req edge
795 }
796 _in[_cnt++] = n; // Stuff over old prec edge
797 if (n != nullptr) n->add_out((Node *)this);
798 Compile::current()->record_modified_node(this);
799 }
800
801 //---------------------------add_req_batch-------------------------------------
802 // Add a new required input at the end
803 void Node::add_req_batch( Node *n, uint m ) {
804 assert( is_not_dead(n), "can not use dead node");
805 // check various edge cases
806 if ((int)m <= 1) {
807 assert((int)m >= 0, "oob");
808 if (m != 0) add_req(n);
809 return;
810 }
811
812 // Look to see if I can move precedence down one without reallocating
813 if( (_cnt+m) > _max || _in[_max-m] )
814 grow( _max+m );
815
816 // Find a precedence edge to move
817 if( _in[_cnt] != nullptr ) { // Next precedence edge is busy?
818 uint i;
819 for( i=_cnt; i<_max; i++ )
820 if( _in[i] == nullptr ) // Find the null at end of prec edge list
821 break; // There must be one, since we grew the array
822 // Slide all the precs over by m positions (assume #prec << m).
823 Copy::conjoint_words_to_higher((HeapWord*)&_in[_cnt], (HeapWord*)&_in[_cnt+m], ((i-_cnt)*sizeof(Node*)));
824 }
825
826 // Stuff over the old prec edges
827 for(uint i=0; i<m; i++ ) {
828 _in[_cnt++] = n;
829 }
830
831 // Insert multiple out edges on the node.
832 if (n != nullptr && !n->is_top()) {
833 for(uint i=0; i<m; i++ ) {
834 n->add_out((Node *)this);
835 }
836 }
837 Compile::current()->record_modified_node(this);
838 }
839
840 //------------------------------del_req----------------------------------------
841 // Delete the required edge and compact the edge array
842 void Node::del_req( uint idx ) {
843 assert( idx < _cnt, "oob");
844 assert( !VerifyHashTableKeys || _hash_lock == 0,
845 "remove node from hash table before modifying it");
846 // First remove corresponding def-use edge
847 Node *n = in(idx);
848 if (n != nullptr) n->del_out((Node *)this);
849 _in[idx] = in(--_cnt); // Compact the array
850 // Avoid spec violation: Gap in prec edges.
851 close_prec_gap_at(_cnt);
852 Compile::current()->record_modified_node(this);
853 }
854
855 //------------------------------del_req_ordered--------------------------------
856 // Delete the required edge and compact the edge array with preserved order
857 void Node::del_req_ordered( uint idx ) {
858 assert( idx < _cnt, "oob");
859 assert( !VerifyHashTableKeys || _hash_lock == 0,
860 "remove node from hash table before modifying it");
861 // First remove corresponding def-use edge
862 Node *n = in(idx);
863 if (n != nullptr) n->del_out((Node *)this);
864 if (idx < --_cnt) { // Not last edge ?
865 Copy::conjoint_words_to_lower((HeapWord*)&_in[idx+1], (HeapWord*)&_in[idx], ((_cnt-idx)*sizeof(Node*)));
866 }
867 // Avoid spec violation: Gap in prec edges.
868 close_prec_gap_at(_cnt);
869 Compile::current()->record_modified_node(this);
870 }
871
872 //------------------------------ins_req----------------------------------------
873 // Insert a new required input at the end
874 void Node::ins_req( uint idx, Node *n ) {
875 assert( is_not_dead(n), "can not use dead node");
876 add_req(nullptr); // Make space
877 assert( idx < _max, "Must have allocated enough space");
878 // Slide over
879 if(_cnt-idx-1 > 0) {
880 Copy::conjoint_words_to_higher((HeapWord*)&_in[idx], (HeapWord*)&_in[idx+1], ((_cnt-idx-1)*sizeof(Node*)));
881 }
882 _in[idx] = n; // Stuff over old required edge
883 if (n != nullptr) n->add_out((Node *)this); // Add reciprocal def-use edge
884 Compile::current()->record_modified_node(this);
885 }
886
887 //-----------------------------find_edge---------------------------------------
888 int Node::find_edge(Node* n) {
889 for (uint i = 0; i < len(); i++) {
890 if (_in[i] == n) return i;
891 }
892 return -1;
893 }
894
895 //----------------------------replace_edge-------------------------------------
896 int Node::replace_edge(Node* old, Node* neww, PhaseGVN* gvn) {
897 if (old == neww) return 0; // nothing to do
898 uint nrep = 0;
899 for (uint i = 0; i < len(); i++) {
900 if (in(i) == old) {
901 if (i < req()) {
902 if (gvn != nullptr) {
903 set_req_X(i, neww, gvn);
904 } else {
905 set_req(i, neww);
906 }
907 } else {
908 assert(gvn == nullptr || gvn->is_IterGVN() == nullptr, "no support for igvn here");
909 assert(find_prec_edge(neww) == -1, "spec violation: duplicated prec edge (node %d -> %d)", _idx, neww->_idx);
910 set_prec(i, neww);
911 }
912 nrep++;
913 }
914 }
915 return nrep;
916 }
917
918 /**
919 * Replace input edges in the range pointing to 'old' node.
920 */
921 int Node::replace_edges_in_range(Node* old, Node* neww, int start, int end, PhaseGVN* gvn) {
922 if (old == neww) return 0; // nothing to do
923 uint nrep = 0;
924 for (int i = start; i < end; i++) {
925 if (in(i) == old) {
926 set_req_X(i, neww, gvn);
927 nrep++;
928 }
929 }
930 return nrep;
931 }
932
933 //-------------------------disconnect_inputs-----------------------------------
934 // null out all inputs to eliminate incoming Def-Use edges.
935 void Node::disconnect_inputs(Compile* C) {
936 // the layout of Node::_in
937 // r: a required input, null is allowed
938 // p: a precedence, null values are all at the end
939 // -----------------------------------
940 // |r|...|r|p|...|p|null|...|null|
941 // | |
942 // req() len()
943 // -----------------------------------
944 for (uint i = 0; i < req(); ++i) {
945 if (in(i) != nullptr) {
946 set_req(i, nullptr);
947 }
948 }
949
950 // Remove precedence edges if any exist
951 // Note: Safepoints may have precedence edges, even during parsing
952 for (uint i = len(); i > req(); ) {
953 rm_prec(--i); // no-op if _in[i] is null
954 }
955
956 #ifdef ASSERT
957 // sanity check
958 for (uint i = 0; i < len(); ++i) {
959 assert(_in[i] == nullptr, "disconnect_inputs() failed!");
960 }
961 #endif
962
963 // Node::destruct requires all out edges be deleted first
964 // DEBUG_ONLY(destruct();) // no reuse benefit expected
965 C->record_dead_node(_idx);
966 }
967
968 //-----------------------------uncast---------------------------------------
969 // %%% Temporary, until we sort out CheckCastPP vs. CastPP.
970 // Strip away casting. (It is depth-limited.)
971 // Optionally, keep casts with dependencies.
972 Node* Node::uncast(bool keep_deps) const {
973 // Should be inline:
974 //return is_ConstraintCast() ? uncast_helper(this) : (Node*) this;
975 if (is_ConstraintCast()) {
976 return uncast_helper(this, keep_deps);
977 } else {
978 return (Node*) this;
979 }
980 }
981
982 // Find out of current node that matches opcode.
983 Node* Node::find_out_with(int opcode) {
984 for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
985 Node* use = fast_out(i);
986 if (use->Opcode() == opcode) {
987 return use;
988 }
989 }
990 return nullptr;
991 }
992
993 // Return true if the current node has an out that matches opcode.
994 bool Node::has_out_with(int opcode) {
995 return (find_out_with(opcode) != nullptr);
996 }
997
998 // Return true if the current node has an out that matches any of the opcodes.
999 bool Node::has_out_with(int opcode1, int opcode2, int opcode3, int opcode4) {
1000 for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
1001 int opcode = fast_out(i)->Opcode();
1002 if (opcode == opcode1 || opcode == opcode2 || opcode == opcode3 || opcode == opcode4) {
1003 return true;
1004 }
1005 }
1006 return false;
1007 }
1008
1009
1010 //---------------------------uncast_helper-------------------------------------
1011 Node* Node::uncast_helper(const Node* p, bool keep_deps) {
1012 #ifdef ASSERT
1013 // If we end up traversing more nodes than we actually have,
1014 // it is definitely an infinite loop.
1015 uint max_depth = Compile::current()->unique();
1016 uint depth_count = 0;
1017 const Node* orig_p = p;
1018 #endif
1019
1020 while (true) {
1021 #ifdef ASSERT
1022 if (depth_count++ >= max_depth) {
1023 orig_p->dump(4);
1024 if (p != orig_p) {
1025 p->dump(1);
1026 }
1027 fatal("infinite loop in Node::uncast_helper");
1028 }
1029 #endif
1030 if (p == nullptr || p->req() != 2) {
1031 break;
1032 } else if (p->is_ConstraintCast()) {
1033 if (keep_deps && p->as_ConstraintCast()->carry_dependency()) {
1034 break; // stop at casts with dependencies
1035 }
1036 p = p->in(1);
1037 } else {
1038 break;
1039 }
1040 }
1041 return (Node*) p;
1042 }
1043
1044 //------------------------------add_prec---------------------------------------
1045 // Add a new precedence input. Precedence inputs are unordered, with
1046 // duplicates removed and nulls packed down at the end.
1047 void Node::add_prec( Node *n ) {
1048 assert( is_not_dead(n), "can not use dead node");
1049
1050 // Check for null at end
1051 if( _cnt >= _max || in(_max-1) )
1052 grow( _max+1 );
1053
1054 // Find a precedence edge to move
1055 uint i = _cnt;
1056 while( in(i) != nullptr ) {
1057 if (in(i) == n) return; // Avoid spec violation: duplicated prec edge.
1058 i++;
1059 }
1060 _in[i] = n; // Stuff prec edge over null
1061 if ( n != nullptr) n->add_out((Node *)this); // Add mirror edge
1062
1063 #ifdef ASSERT
1064 while ((++i)<_max) { assert(_in[i] == nullptr, "spec violation: Gap in prec edges (node %d)", _idx); }
1065 #endif
1066 Compile::current()->record_modified_node(this);
1067 }
1068
1069 //------------------------------rm_prec----------------------------------------
1070 // Remove a precedence input. Precedence inputs are unordered, with
1071 // duplicates removed and nulls packed down at the end.
1072 void Node::rm_prec( uint j ) {
1073 assert(j < _max, "oob: i=%d, _max=%d", j, _max);
1074 assert(j >= _cnt, "not a precedence edge");
1075 if (_in[j] == nullptr) return; // Avoid spec violation: Gap in prec edges.
1076 _in[j]->del_out((Node *)this);
1077 close_prec_gap_at(j);
1078 Compile::current()->record_modified_node(this);
1079 }
1080
1081 //------------------------------size_of----------------------------------------
1082 uint Node::size_of() const { return sizeof(*this); }
1083
1084 //------------------------------ideal_reg--------------------------------------
1085 uint Node::ideal_reg() const { return 0; }
1086
1087 //------------------------------jvms-------------------------------------------
1088 JVMState* Node::jvms() const { return nullptr; }
1089
1090 #ifdef ASSERT
1091 //------------------------------jvms-------------------------------------------
1092 bool Node::verify_jvms(const JVMState* using_jvms) const {
1093 for (JVMState* jvms = this->jvms(); jvms != nullptr; jvms = jvms->caller()) {
1094 if (jvms == using_jvms) return true;
1095 }
1096 return false;
1097 }
1098
1099 //------------------------------init_NodeProperty------------------------------
1100 void Node::init_NodeProperty() {
1101 assert(_max_classes <= max_juint, "too many NodeProperty classes");
1102 assert(max_flags() <= max_juint, "too many NodeProperty flags");
1103 }
1104
1105 //-----------------------------max_flags---------------------------------------
1106 juint Node::max_flags() {
1107 return (PD::_last_flag << 1) - 1; // allow flags combination
1108 }
1109 #endif
1110
1111 //------------------------------format-----------------------------------------
1112 // Print as assembly
1113 void Node::format( PhaseRegAlloc *, outputStream *st ) const {}
1114 //------------------------------emit-------------------------------------------
1115 // Emit bytes using C2_MacroAssembler
1116 void Node::emit(C2_MacroAssembler *masm, PhaseRegAlloc *ra_) const {}
1117 //------------------------------size-------------------------------------------
1118 // Size of instruction in bytes
1119 uint Node::size(PhaseRegAlloc *ra_) const { return 0; }
1120
1121 //------------------------------CFG Construction-------------------------------
1122 // Nodes that end basic blocks, e.g. IfTrue/IfFalse, JumpProjNode, Root,
1123 // Goto and Return.
1124 const Node *Node::is_block_proj() const { return nullptr; }
1125
1126 // Minimum guaranteed type
1127 const Type *Node::bottom_type() const { return Type::BOTTOM; }
1128
1129
1130 //------------------------------raise_bottom_type------------------------------
1131 // Get the worst-case Type output for this Node.
1132 void Node::raise_bottom_type(const Type* new_type) {
1133 if (is_Type()) {
1134 TypeNode *n = this->as_Type();
1135 if (VerifyAliases) {
1136 assert(new_type->higher_equal_speculative(n->type()), "new type must refine old type");
1137 }
1138 n->set_type(new_type);
1139 } else if (is_Load()) {
1140 LoadNode *n = this->as_Load();
1141 if (VerifyAliases) {
1142 assert(new_type->higher_equal_speculative(n->type()), "new type must refine old type");
1143 }
1144 n->set_type(new_type);
1145 }
1146 }
1147
1148 //------------------------------Identity---------------------------------------
1149 // Return a node that the given node is equivalent to.
1150 Node* Node::Identity(PhaseGVN* phase) {
1151 return this; // Default to no identities
1152 }
1153
1154 //------------------------------Value------------------------------------------
1155 // Compute a new Type for a node using the Type of the inputs.
1156 const Type* Node::Value(PhaseGVN* phase) const {
1157 return bottom_type(); // Default to worst-case Type
1158 }
1159
1160 //------------------------------Ideal------------------------------------------
1161 //
1162 // 'Idealize' the graph rooted at this Node.
1163 //
1164 // In order to be efficient and flexible there are some subtle invariants
1165 // these Ideal calls need to hold. Some of the flag bits for '-XX:VerifyIterativeGVN'
1166 // can help with validating these invariants, although they are too slow to have on by default:
1167 // - '-XX:VerifyIterativeGVN=1' checks the def-use info
1168 // - '-XX:VerifyIterativeGVN=100000' checks the return value
1169 // If you are hacking an Ideal call, be sure to use these.
1170 //
1171 // The Ideal call almost arbitrarily reshape the graph rooted at the 'this'
1172 // pointer. If ANY change is made, it must return the root of the reshaped
1173 // graph - even if the root is the same Node. Example: swapping the inputs
1174 // to an AddINode gives the same answer and same root, but you still have to
1175 // return the 'this' pointer instead of null. If the node was already dead
1176 // before the Ideal call, this rule does not apply, and it is fine to return
1177 // nullptr even if modifications were made.
1178 //
1179 // You cannot return an OLD Node, except for the 'this' pointer. Use the
1180 // Identity call to return an old Node; basically if Identity can find
1181 // another Node have the Ideal call make no change and return null.
1182 // Example: AddINode::Ideal must check for add of zero; in this case it
1183 // returns null instead of doing any graph reshaping.
1184 //
1185 // You cannot modify any old Nodes except for the 'this' pointer. Due to
1186 // sharing there may be other users of the old Nodes relying on their current
1187 // semantics. Modifying them will break the other users.
1188 // Example: when reshape "(X+3)+4" into "X+7" you must leave the Node for
1189 // "X+3" unchanged in case it is shared.
1190 //
1191 // If you modify the 'this' pointer's inputs, you should use
1192 // 'set_req'. If you are making a new Node (either as the new root or
1193 // some new internal piece) you may use 'init_req' to set the initial
1194 // value. You can make a new Node with either 'new' or 'clone'. In
1195 // either case, def-use info is correctly maintained.
1196 //
1197 // Example: reshape "(X+3)+4" into "X+7":
1198 // set_req(1, in(1)->in(1));
1199 // set_req(2, phase->intcon(7));
1200 // return this;
1201 // Example: reshape "X*4" into "X<<2"
1202 // return new LShiftINode(in(1), phase->intcon(2));
1203 //
1204 // You must call 'phase->transform(X)' on any new Nodes X you make, except
1205 // for the returned root node. Example: reshape "X*31" with "(X<<5)-X".
1206 // Node *shift=phase->transform(new LShiftINode(in(1),phase->intcon(5)));
1207 // return new AddINode(shift, in(1));
1208 //
1209 // When making a Node for a constant use 'phase->makecon' or 'phase->intcon'.
1210 // These forms are faster than 'phase->transform(new ConNode())' and Do
1211 // The Right Thing with def-use info.
1212 //
1213 // You cannot bury the 'this' Node inside of a graph reshape. If the reshaped
1214 // graph uses the 'this' Node it must be the root. If you want a Node with
1215 // the same Opcode as the 'this' pointer use 'clone'.
1216 //
1217 Node *Node::Ideal(PhaseGVN *phase, bool can_reshape) {
1218 return nullptr; // Default to being Ideal already
1219 }
1220
1221 // Some nodes have specific Ideal subgraph transformations only if they are
1222 // unique users of specific nodes. Such nodes should be put on IGVN worklist
1223 // for the transformations to happen.
1224 bool Node::has_special_unique_user() const {
1225 assert(outcnt() == 1, "match only for unique out");
1226 Node* n = unique_out();
1227 int op = Opcode();
1228 if (this->is_Store()) {
1229 // Condition for back-to-back stores folding.
1230 return n->Opcode() == op && n->in(MemNode::Memory) == this;
1231 } else if ((this->is_Load() || this->is_DecodeN() || this->is_Phi() || this->is_Con()) && n->Opcode() == Op_MemBarAcquire) {
1232 // Condition for removing an unused LoadNode or DecodeNNode from the MemBarAcquire precedence input
1233 return true;
1234 } else if (this->is_Load() && n->is_Move()) {
1235 // Condition for MoveX2Y (LoadX mem) => LoadY mem
1236 return true;
1237 } else if (op == Op_AddL) {
1238 // Condition for convL2I(addL(x,y)) ==> addI(convL2I(x),convL2I(y))
1239 return n->Opcode() == Op_ConvL2I && n->in(1) == this;
1240 } else if (op == Op_SubI || op == Op_SubL) {
1241 // Condition for subI(x,subI(y,z)) ==> subI(addI(x,z),y)
1242 return n->Opcode() == op && n->in(2) == this;
1243 } else if (is_If() && (n->is_IfFalse() || n->is_IfTrue())) {
1244 // See IfProjNode::Identity()
1245 return true;
1246 } else if ((is_IfFalse() || is_IfTrue()) && n->is_If()) {
1247 // See IfNode::fold_compares
1248 return true;
1249 } else if (n->Opcode() == Op_XorV || n->Opcode() == Op_XorVMask) {
1250 // Condition for XorVMask(VectorMaskCmp(x,y,cond), MaskAll(true)) ==> VectorMaskCmp(x,y,ncond)
1251 return true;
1252 } else {
1253 return false;
1254 }
1255 };
1256
1257 //--------------------------find_exact_control---------------------------------
1258 // Skip Proj and CatchProj nodes chains. Check for Null and Top.
1259 Node* Node::find_exact_control(Node* ctrl) {
1260 if (ctrl == nullptr && this->is_Region())
1261 ctrl = this->as_Region()->is_copy();
1262
1263 if (ctrl != nullptr && ctrl->is_CatchProj()) {
1264 if (ctrl->as_CatchProj()->_con == CatchProjNode::fall_through_index)
1265 ctrl = ctrl->in(0);
1266 if (ctrl != nullptr && !ctrl->is_top())
1267 ctrl = ctrl->in(0);
1268 }
1269
1270 if (ctrl != nullptr && ctrl->is_Proj())
1271 ctrl = ctrl->in(0);
1272
1273 return ctrl;
1274 }
1275
1276 //--------------------------dominates------------------------------------------
1277 // Helper function for MemNode::all_controls_dominate().
1278 // Check if 'this' control node dominates or equal to 'sub' control node.
1279 // We already know that if any path back to Root or Start reaches 'this',
1280 // then all paths so, so this is a simple search for one example,
1281 // not an exhaustive search for a counterexample.
1282 Node::DomResult Node::dominates(Node* sub, Node_List &nlist) {
1283 assert(this->is_CFG(), "expecting control");
1284 assert(sub != nullptr && sub->is_CFG(), "expecting control");
1285
1286 // detect dead cycle without regions
1287 int iterations_without_region_limit = DominatorSearchLimit;
1288
1289 Node* orig_sub = sub;
1290 Node* dom = this;
1291 bool met_dom = false;
1292 nlist.clear();
1293
1294 // Walk 'sub' backward up the chain to 'dom', watching for regions.
1295 // After seeing 'dom', continue up to Root or Start.
1296 // If we hit a region (backward split point), it may be a loop head.
1297 // Keep going through one of the region's inputs. If we reach the
1298 // same region again, go through a different input. Eventually we
1299 // will either exit through the loop head, or give up.
1300 // (If we get confused, break out and return a conservative 'false'.)
1301 while (sub != nullptr) {
1302 if (sub->is_top()) {
1303 // Conservative answer for dead code.
1304 return DomResult::EncounteredDeadCode;
1305 }
1306 if (sub == dom) {
1307 if (nlist.size() == 0) {
1308 // No Region nodes except loops were visited before and the EntryControl
1309 // path was taken for loops: it did not walk in a cycle.
1310 return DomResult::Dominate;
1311 } else if (met_dom) {
1312 break; // already met before: walk in a cycle
1313 } else {
1314 // Region nodes were visited. Continue walk up to Start or Root
1315 // to make sure that it did not walk in a cycle.
1316 met_dom = true; // first time meet
1317 iterations_without_region_limit = DominatorSearchLimit; // Reset
1318 }
1319 }
1320 if (sub->is_Start() || sub->is_Root()) {
1321 // Success if we met 'dom' along a path to Start or Root.
1322 // We assume there are no alternative paths that avoid 'dom'.
1323 // (This assumption is up to the caller to ensure!)
1324 return met_dom ? DomResult::Dominate : DomResult::NotDominate;
1325 }
1326 Node* up = sub->in(0);
1327 // Normalize simple pass-through regions and projections:
1328 up = sub->find_exact_control(up);
1329 // If sub == up, we found a self-loop. Try to push past it.
1330 if (sub == up && sub->is_Loop()) {
1331 // Take loop entry path on the way up to 'dom'.
1332 up = sub->in(1); // in(LoopNode::EntryControl);
1333 } else if (sub == up && sub->is_Region() && sub->req() == 2) {
1334 // Take in(1) path on the way up to 'dom' for regions with only one input
1335 up = sub->in(1);
1336 } else if (sub == up && sub->is_Region()) {
1337 // Try both paths for Regions with 2 input paths (it may be a loop head).
1338 // It could give conservative 'false' answer without information
1339 // which region's input is the entry path.
1340 iterations_without_region_limit = DominatorSearchLimit; // Reset
1341
1342 bool region_was_visited_before = false;
1343 // Was this Region node visited before?
1344 // If so, we have reached it because we accidentally took a
1345 // loop-back edge from 'sub' back into the body of the loop,
1346 // and worked our way up again to the loop header 'sub'.
1347 // So, take the first unexplored path on the way up to 'dom'.
1348 for (int j = nlist.size() - 1; j >= 0; j--) {
1349 intptr_t ni = (intptr_t)nlist.at(j);
1350 Node* visited = (Node*)(ni & ~1);
1351 bool visited_twice_already = ((ni & 1) != 0);
1352 if (visited == sub) {
1353 if (visited_twice_already) {
1354 // Visited 2 paths, but still stuck in loop body. Give up.
1355 return DomResult::NotDominate;
1356 }
1357 // The Region node was visited before only once.
1358 // (We will repush with the low bit set, below.)
1359 nlist.remove(j);
1360 // We will find a new edge and re-insert.
1361 region_was_visited_before = true;
1362 break;
1363 }
1364 }
1365
1366 // Find an incoming edge which has not been seen yet; walk through it.
1367 assert(up == sub, "");
1368 uint skip = region_was_visited_before ? 1 : 0;
1369 for (uint i = 1; i < sub->req(); i++) {
1370 Node* in = sub->in(i);
1371 if (in != nullptr && !in->is_top() && in != sub) {
1372 if (skip == 0) {
1373 up = in;
1374 break;
1375 }
1376 --skip; // skip this nontrivial input
1377 }
1378 }
1379
1380 // Set 0 bit to indicate that both paths were taken.
1381 nlist.push((Node*)((intptr_t)sub + (region_was_visited_before ? 1 : 0)));
1382 }
1383
1384 if (up == sub) {
1385 break; // some kind of tight cycle
1386 }
1387 if (up == orig_sub && met_dom) {
1388 // returned back after visiting 'dom'
1389 break; // some kind of cycle
1390 }
1391 if (--iterations_without_region_limit < 0) {
1392 break; // dead cycle
1393 }
1394 sub = up;
1395 }
1396
1397 // Did not meet Root or Start node in pred. chain.
1398 return DomResult::NotDominate;
1399 }
1400
1401 //------------------------------remove_dead_region-----------------------------
1402 // This control node is dead. Follow the subgraph below it making everything
1403 // using it dead as well. This will happen normally via the usual IterGVN
1404 // worklist but this call is more efficient. Do not update use-def info
1405 // inside the dead region, just at the borders.
1406 static void kill_dead_code( Node *dead, PhaseIterGVN *igvn ) {
1407 // Con's are a popular node to re-hit in the hash table again.
1408 if( dead->is_Con() ) return;
1409
1410 ResourceMark rm;
1411 Node_List nstack;
1412 VectorSet dead_set; // notify uses only once
1413
1414 Node *top = igvn->C->top();
1415 nstack.push(dead);
1416 bool has_irreducible_loop = igvn->C->has_irreducible_loop();
1417
1418 while (nstack.size() > 0) {
1419 dead = nstack.pop();
1420 if (!dead_set.test_set(dead->_idx)) {
1421 // If dead has any live uses, those are now still attached. Notify them before we lose them.
1422 igvn->add_users_to_worklist(dead);
1423 }
1424 if (dead->Opcode() == Op_SafePoint) {
1425 dead->as_SafePoint()->disconnect_from_root(igvn);
1426 }
1427 if (dead->outcnt() > 0) {
1428 // Keep dead node on stack until all uses are processed.
1429 nstack.push(dead);
1430 // For all Users of the Dead... ;-)
1431 for (DUIterator_Last kmin, k = dead->last_outs(kmin); k >= kmin; ) {
1432 Node* use = dead->last_out(k);
1433 igvn->hash_delete(use); // Yank from hash table prior to mod
1434 if (use->in(0) == dead) { // Found another dead node
1435 assert (!use->is_Con(), "Control for Con node should be Root node.");
1436 use->set_req(0, top); // Cut dead edge to prevent processing
1437 nstack.push(use); // the dead node again.
1438 } else if (!has_irreducible_loop && // Backedge could be alive in irreducible loop
1439 use->is_Loop() && !use->is_Root() && // Don't kill Root (RootNode extends LoopNode)
1440 use->in(LoopNode::EntryControl) == dead) { // Dead loop if its entry is dead
1441 use->set_req(LoopNode::EntryControl, top); // Cut dead edge to prevent processing
1442 use->set_req(0, top); // Cut self edge
1443 nstack.push(use);
1444 } else { // Else found a not-dead user
1445 // Dead if all inputs are top or null
1446 bool dead_use = !use->is_Root(); // Keep empty graph alive
1447 for (uint j = 1; j < use->req(); j++) {
1448 Node* in = use->in(j);
1449 if (in == dead) { // Turn all dead inputs into TOP
1450 use->set_req(j, top);
1451 } else if (in != nullptr && !in->is_top()) {
1452 dead_use = false;
1453 }
1454 }
1455 if (dead_use) {
1456 if (use->is_Region()) {
1457 use->set_req(0, top); // Cut self edge
1458 }
1459 nstack.push(use);
1460 } else {
1461 igvn->_worklist.push(use);
1462 }
1463 }
1464 // Refresh the iterator, since any number of kills might have happened.
1465 k = dead->last_outs(kmin);
1466 }
1467 } else { // (dead->outcnt() == 0)
1468 // Done with outputs.
1469 igvn->hash_delete(dead);
1470 igvn->_worklist.remove(dead);
1471 igvn->set_type(dead, Type::TOP);
1472 // Kill all inputs to the dead guy
1473 for (uint i=0; i < dead->req(); i++) {
1474 Node *n = dead->in(i); // Get input to dead guy
1475 if (n != nullptr && !n->is_top()) { // Input is valid?
1476 dead->set_req(i, top); // Smash input away
1477 if (n->outcnt() == 0) { // Input also goes dead?
1478 if (!n->is_Con())
1479 nstack.push(n); // Clear it out as well
1480 } else if (n->outcnt() == 1 &&
1481 n->has_special_unique_user()) {
1482 igvn->add_users_to_worklist( n );
1483 } else if (n->outcnt() <= 2 && n->is_Store()) {
1484 // Push store's uses on worklist to enable folding optimization for
1485 // store/store and store/load to the same address.
1486 // The restriction (outcnt() <= 2) is the same as in set_req_X()
1487 // and remove_globally_dead_node().
1488 igvn->add_users_to_worklist( n );
1489 } else if (dead->is_data_proj_of_pure_function(n)) {
1490 igvn->_worklist.push(n);
1491 } else {
1492 BarrierSet::barrier_set()->barrier_set_c2()->enqueue_useful_gc_barrier(igvn, n);
1493 }
1494 }
1495 }
1496 igvn->C->remove_useless_node(dead);
1497 } // (dead->outcnt() == 0)
1498 } // while (nstack.size() > 0) for outputs
1499 return;
1500 }
1501
1502 //------------------------------remove_dead_region-----------------------------
1503 bool Node::remove_dead_region(PhaseGVN *phase, bool can_reshape) {
1504 Node *n = in(0);
1505 if( !n ) return false;
1506 // Lost control into this guy? I.e., it became unreachable?
1507 // Aggressively kill all unreachable code.
1508 if (can_reshape && n->is_top()) {
1509 kill_dead_code(this, phase->is_IterGVN());
1510 return false; // Node is dead.
1511 }
1512
1513 if( n->is_Region() && n->as_Region()->is_copy() ) {
1514 Node *m = n->nonnull_req();
1515 set_req(0, m);
1516 return true;
1517 }
1518 return false;
1519 }
1520
1521 //------------------------------hash-------------------------------------------
1522 // Hash function over Nodes.
1523 uint Node::hash() const {
1524 uint sum = 0;
1525 for( uint i=0; i<_cnt; i++ ) // Add in all inputs
1526 sum = (sum<<1)-(uintptr_t)in(i); // Ignore embedded nulls
1527 return (sum>>2) + _cnt + Opcode();
1528 }
1529
1530 //------------------------------cmp--------------------------------------------
1531 // Compare special parts of simple Nodes
1532 bool Node::cmp( const Node &n ) const {
1533 return true; // Must be same
1534 }
1535
1536 //------------------------------rematerialize-----------------------------------
1537 // Should we clone rather than spill this instruction?
1538 bool Node::rematerialize() const {
1539 if ( is_Mach() )
1540 return this->as_Mach()->rematerialize();
1541 else
1542 return (_flags & Flag_rematerialize) != 0;
1543 }
1544
1545 //------------------------------needs_anti_dependence_check---------------------
1546 // Nodes which use memory without consuming it, hence need antidependences.
1547 bool Node::needs_anti_dependence_check() const {
1548 if (req() < 2 || (_flags & Flag_needs_anti_dependence_check) == 0) {
1549 return false;
1550 }
1551 return in(1)->bottom_type()->has_memory();
1552 }
1553
1554 // Get an integer constant from a ConNode (or CastIINode).
1555 // Return a default value if there is no apparent constant here.
1556 const TypeInt* Node::find_int_type() const {
1557 if (this->is_Type()) {
1558 return this->as_Type()->type()->isa_int();
1559 } else if (this->is_Con()) {
1560 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1561 return this->bottom_type()->isa_int();
1562 }
1563 return nullptr;
1564 }
1565
1566 const TypeInteger* Node::find_integer_type(BasicType bt) const {
1567 if (this->is_Type()) {
1568 return this->as_Type()->type()->isa_integer(bt);
1569 } else if (this->is_Con()) {
1570 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1571 return this->bottom_type()->isa_integer(bt);
1572 }
1573 return nullptr;
1574 }
1575
1576 // Get a pointer constant from a ConstNode.
1577 // Returns the constant if it is a pointer ConstNode
1578 intptr_t Node::get_ptr() const {
1579 assert( Opcode() == Op_ConP, "" );
1580 return ((ConPNode*)this)->type()->is_ptr()->get_con();
1581 }
1582
1583 // Get a narrow oop constant from a ConNNode.
1584 intptr_t Node::get_narrowcon() const {
1585 assert( Opcode() == Op_ConN, "" );
1586 return ((ConNNode*)this)->type()->is_narrowoop()->get_con();
1587 }
1588
1589 // Get a long constant from a ConNode.
1590 // Return a default value if there is no apparent constant here.
1591 const TypeLong* Node::find_long_type() const {
1592 if (this->is_Type()) {
1593 return this->as_Type()->type()->isa_long();
1594 } else if (this->is_Con()) {
1595 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1596 return this->bottom_type()->isa_long();
1597 }
1598 return nullptr;
1599 }
1600
1601
1602 /**
1603 * Return a ptr type for nodes which should have it.
1604 */
1605 const TypePtr* Node::get_ptr_type() const {
1606 const TypePtr* tp = this->bottom_type()->make_ptr();
1607 #ifdef ASSERT
1608 if (tp == nullptr) {
1609 this->dump(1);
1610 assert((tp != nullptr), "unexpected node type");
1611 }
1612 #endif
1613 return tp;
1614 }
1615
1616 // Get a double constant from a ConstNode.
1617 // Returns the constant if it is a double ConstNode
1618 jdouble Node::getd() const {
1619 assert( Opcode() == Op_ConD, "" );
1620 return ((ConDNode*)this)->type()->is_double_constant()->getd();
1621 }
1622
1623 // Get a float constant from a ConstNode.
1624 // Returns the constant if it is a float ConstNode
1625 jfloat Node::getf() const {
1626 assert( Opcode() == Op_ConF, "" );
1627 return ((ConFNode*)this)->type()->is_float_constant()->getf();
1628 }
1629
1630 // Get a half float constant from a ConstNode.
1631 // Returns the constant if it is a float ConstNode
1632 jshort Node::geth() const {
1633 assert( Opcode() == Op_ConH, "" );
1634 return ((ConHNode*)this)->type()->is_half_float_constant()->geth();
1635 }
1636
1637 #ifndef PRODUCT
1638
1639 // Call this from debugger:
1640 Node* old_root() {
1641 Matcher* matcher = Compile::current()->matcher();
1642 if (matcher != nullptr) {
1643 Node* new_root = Compile::current()->root();
1644 Node* old_root = matcher->find_old_node(new_root);
1645 if (old_root != nullptr) {
1646 return old_root;
1647 }
1648 }
1649 tty->print("old_root: not found.\n");
1650 return nullptr;
1651 }
1652
1653 // BFS traverse all reachable nodes from start, call callback on them
1654 template <typename Callback>
1655 void visit_nodes(Node* start, Callback callback, bool traverse_output, bool only_ctrl) {
1656 Unique_Mixed_Node_List worklist;
1657 worklist.add(start);
1658 for (uint i = 0; i < worklist.size(); i++) {
1659 Node* n = worklist[i];
1660 callback(n);
1661 for (uint i = 0; i < n->len(); i++) {
1662 if (!only_ctrl || n->is_Region() || (n->Opcode() == Op_Root) || (i == TypeFunc::Control)) {
1663 // If only_ctrl is set: Add regions, the root node, or control inputs only
1664 worklist.add(n->in(i));
1665 }
1666 }
1667 if (traverse_output && !only_ctrl) {
1668 for (uint i = 0; i < n->outcnt(); i++) {
1669 worklist.add(n->raw_out(i));
1670 }
1671 }
1672 }
1673 }
1674
1675 // BFS traverse from start, return node with idx
1676 static Node* find_node_by_idx(Node* start, uint idx, bool traverse_output, bool only_ctrl) {
1677 ResourceMark rm;
1678 Node* result = nullptr;
1679 auto callback = [&] (Node* n) {
1680 if (n->_idx == idx) {
1681 if (result != nullptr) {
1682 tty->print("find_node_by_idx: " INTPTR_FORMAT " and " INTPTR_FORMAT " both have idx==%d\n",
1683 (uintptr_t)result, (uintptr_t)n, idx);
1684 }
1685 result = n;
1686 }
1687 };
1688 visit_nodes(start, callback, traverse_output, only_ctrl);
1689 return result;
1690 }
1691
1692 static int node_idx_cmp(const Node** n1, const Node** n2) {
1693 return (*n1)->_idx - (*n2)->_idx;
1694 }
1695
1696 static void find_nodes_by_name(Node* start, const char* name) {
1697 ResourceMark rm;
1698 GrowableArray<const Node*> ns;
1699 auto callback = [&] (const Node* n) {
1700 if (StringUtils::is_star_match(name, n->Name())) {
1701 ns.push(n);
1702 }
1703 };
1704 visit_nodes(start, callback, true, false);
1705 ns.sort(node_idx_cmp);
1706 for (int i = 0; i < ns.length(); i++) {
1707 ns.at(i)->dump();
1708 }
1709 }
1710
1711 static void find_nodes_by_dump(Node* start, const char* pattern) {
1712 ResourceMark rm;
1713 GrowableArray<const Node*> ns;
1714 auto callback = [&] (const Node* n) {
1715 stringStream stream;
1716 n->dump("", false, &stream);
1717 if (StringUtils::is_star_match(pattern, stream.base())) {
1718 ns.push(n);
1719 }
1720 };
1721 visit_nodes(start, callback, true, false);
1722 ns.sort(node_idx_cmp);
1723 for (int i = 0; i < ns.length(); i++) {
1724 ns.at(i)->dump();
1725 }
1726 }
1727
1728 // call from debugger: find node with name pattern in new/current graph
1729 // name can contain "*" in match pattern to match any characters
1730 // the matching is case insensitive
1731 void find_nodes_by_name(const char* name) {
1732 Node* root = Compile::current()->root();
1733 find_nodes_by_name(root, name);
1734 }
1735
1736 // call from debugger: find node with name pattern in old graph
1737 // name can contain "*" in match pattern to match any characters
1738 // the matching is case insensitive
1739 void find_old_nodes_by_name(const char* name) {
1740 Node* root = old_root();
1741 find_nodes_by_name(root, name);
1742 }
1743
1744 // call from debugger: find node with dump pattern in new/current graph
1745 // can contain "*" in match pattern to match any characters
1746 // the matching is case insensitive
1747 void find_nodes_by_dump(const char* pattern) {
1748 Node* root = Compile::current()->root();
1749 find_nodes_by_dump(root, pattern);
1750 }
1751
1752 // call from debugger: find node with name pattern in old graph
1753 // can contain "*" in match pattern to match any characters
1754 // the matching is case insensitive
1755 void find_old_nodes_by_dump(const char* pattern) {
1756 Node* root = old_root();
1757 find_nodes_by_dump(root, pattern);
1758 }
1759
1760 // Call this from debugger, search in same graph as n:
1761 Node* find_node(Node* n, const int idx) {
1762 return n->find(idx);
1763 }
1764
1765 // Call this from debugger, search in new nodes:
1766 Node* find_node(const int idx) {
1767 return Compile::current()->root()->find(idx);
1768 }
1769
1770 // Call this from debugger, search in old nodes:
1771 Node* find_old_node(const int idx) {
1772 Node* root = old_root();
1773 return (root == nullptr) ? nullptr : root->find(idx);
1774 }
1775
1776 // Call this from debugger, search in same graph as n:
1777 Node* find_ctrl(Node* n, const int idx) {
1778 return n->find_ctrl(idx);
1779 }
1780
1781 // Call this from debugger, search in new nodes:
1782 Node* find_ctrl(const int idx) {
1783 return Compile::current()->root()->find_ctrl(idx);
1784 }
1785
1786 // Call this from debugger, search in old nodes:
1787 Node* find_old_ctrl(const int idx) {
1788 Node* root = old_root();
1789 return (root == nullptr) ? nullptr : root->find_ctrl(idx);
1790 }
1791
1792 //------------------------------find_ctrl--------------------------------------
1793 // Find an ancestor to this node in the control history with given _idx
1794 Node* Node::find_ctrl(int idx) {
1795 return find(idx, true);
1796 }
1797
1798 //------------------------------find-------------------------------------------
1799 // Tries to find the node with the index |idx| starting from this node. If idx is negative,
1800 // the search also includes forward (out) edges. Returns null if not found.
1801 // If only_ctrl is set, the search will only be done on control nodes. Returns null if
1802 // not found or if the node to be found is not a control node (search will not find it).
1803 Node* Node::find(const int idx, bool only_ctrl) {
1804 ResourceMark rm;
1805 return find_node_by_idx(this, abs(idx), (idx < 0), only_ctrl);
1806 }
1807
1808 class PrintBFS {
1809 public:
1810 PrintBFS(const Node* start, const int max_distance, const Node* target, const char* options, outputStream* st, const frame* fr)
1811 : _start(start), _max_distance(max_distance), _target(target), _options(options), _output(st), _frame(fr),
1812 _dcc(this), _info_uid(cmpkey, hashkey) {}
1813
1814 void run();
1815 private:
1816 // pipeline steps
1817 bool configure();
1818 void collect();
1819 void select();
1820 void select_all();
1821 void select_all_paths();
1822 void select_shortest_path();
1823 void sort();
1824 void print();
1825
1826 // inputs
1827 const Node* _start;
1828 const int _max_distance;
1829 const Node* _target;
1830 const char* _options;
1831 outputStream* _output;
1832 const frame* _frame;
1833
1834 // options
1835 bool _traverse_inputs = false;
1836 bool _traverse_outputs = false;
1837 struct Filter {
1838 bool _control = false;
1839 bool _memory = false;
1840 bool _data = false;
1841 bool _mixed = false;
1842 bool _other = false;
1843 bool is_empty() const {
1844 return !(_control || _memory || _data || _mixed || _other);
1845 }
1846 void set_all() {
1847 _control = true;
1848 _memory = true;
1849 _data = true;
1850 _mixed = true;
1851 _other = true;
1852 }
1853 // Check if the filter accepts the node. Go by the type categories, but also all CFG nodes
1854 // are considered to have control.
1855 bool accepts(const Node* n) {
1856 const Type* t = n->bottom_type();
1857 return ( _data && t->has_category(Type::Category::Data) ) ||
1858 ( _memory && t->has_category(Type::Category::Memory) ) ||
1859 ( _mixed && t->has_category(Type::Category::Mixed) ) ||
1860 ( _control && (t->has_category(Type::Category::Control) || n->is_CFG()) ) ||
1861 ( _other && t->has_category(Type::Category::Other) );
1862 }
1863 };
1864 Filter _filter_visit;
1865 Filter _filter_boundary;
1866 bool _sort_idx = false;
1867 bool _all_paths = false;
1868 bool _use_color = false;
1869 bool _print_blocks = false;
1870 bool _print_old = false;
1871 bool _dump_only = false;
1872 bool _print_igv = false;
1873
1874 void print_options_help(bool print_examples);
1875 bool parse_options();
1876
1877 public:
1878 class DumpConfigColored : public Node::DumpConfig {
1879 public:
1880 DumpConfigColored(PrintBFS* bfs) : _bfs(bfs) {};
1881 virtual void pre_dump(outputStream* st, const Node* n);
1882 virtual void post_dump(outputStream* st);
1883 private:
1884 PrintBFS* _bfs;
1885 };
1886 private:
1887 DumpConfigColored _dcc;
1888
1889 // node info
1890 static Node* old_node(const Node* n); // mach node -> prior IR node
1891 void print_node_idx(const Node* n);
1892 void print_block_id(const Block* b);
1893 void print_node_block(const Node* n); // _pre_order, head idx, _idom, _dom_depth
1894
1895 // traversal data structures
1896 GrowableArray<const Node*> _worklist; // BFS queue
1897 void maybe_traverse(const Node* src, const Node* dst);
1898
1899 // node info annotation
1900 class Info {
1901 public:
1902 Info() : Info(nullptr, 0) {};
1903 Info(const Node* node, int distance)
1904 : _node(node), _distance_from_start(distance) {};
1905 const Node* node() const { return _node; };
1906 int distance() const { return _distance_from_start; };
1907 int distance_from_target() const { return _distance_from_target; }
1908 void set_distance_from_target(int d) { _distance_from_target = d; }
1909 GrowableArray<const Node*> edge_bwd; // pointing toward _start
1910 bool is_marked() const { return _mark; } // marked to keep during select
1911 void set_mark() { _mark = true; }
1912 private:
1913 const Node* _node;
1914 int _distance_from_start; // distance from _start
1915 int _distance_from_target = 0; // distance from _target if _all_paths
1916 bool _mark = false;
1917 };
1918 Dict _info_uid; // Node -> uid
1919 GrowableArray<Info> _info; // uid -> info
1920
1921 Info* find_info(const Node* n) {
1922 size_t uid = (size_t)_info_uid[n];
1923 if (uid == 0) {
1924 return nullptr;
1925 }
1926 return &_info.at((int)uid);
1927 }
1928
1929 void make_info(const Node* node, const int distance) {
1930 assert(find_info(node) == nullptr, "node does not yet have info");
1931 size_t uid = _info.length() + 1;
1932 _info_uid.Insert((void*)node, (void*)uid);
1933 _info.at_put_grow((int)uid, Info(node, distance));
1934 assert(find_info(node)->node() == node, "stored correct node");
1935 };
1936
1937 // filled by sort, printed by print
1938 GrowableArray<const Node*> _print_list;
1939
1940 // print header + node table
1941 void print_header() const;
1942 void print_node(const Node* n);
1943 };
1944
1945 void PrintBFS::run() {
1946 if (!configure()) {
1947 return;
1948 }
1949 collect();
1950 select();
1951 sort();
1952 print();
1953 }
1954
1955 // set up configuration for BFS and print
1956 bool PrintBFS::configure() {
1957 if (_max_distance < 0) {
1958 _output->print_cr("dump_bfs: max_distance must be non-negative!");
1959 return false;
1960 }
1961 return parse_options();
1962 }
1963
1964 // BFS traverse according to configuration, fill worklist and info
1965 void PrintBFS::collect() {
1966 maybe_traverse(_start, _start);
1967 int pos = 0;
1968 while (pos < _worklist.length()) {
1969 const Node* n = _worklist.at(pos++); // next node to traverse
1970 Info* info = find_info(n);
1971 if (!_filter_visit.accepts(n) && n != _start) {
1972 continue; // we hit boundary, do not traverse further
1973 }
1974 if (n != _start && n->is_Root()) {
1975 continue; // traversing through root node would lead to unrelated nodes
1976 }
1977 if (_traverse_inputs && _max_distance > info->distance()) {
1978 for (uint i = 0; i < n->req(); i++) {
1979 maybe_traverse(n, n->in(i));
1980 }
1981 }
1982 if (_traverse_outputs && _max_distance > info->distance()) {
1983 for (uint i = 0; i < n->outcnt(); i++) {
1984 maybe_traverse(n, n->raw_out(i));
1985 }
1986 }
1987 }
1988 }
1989
1990 // go through work list, mark those that we want to print
1991 void PrintBFS::select() {
1992 if (_target == nullptr ) {
1993 select_all();
1994 } else {
1995 if (find_info(_target) == nullptr) {
1996 _output->print_cr("Could not find target in BFS.");
1997 return;
1998 }
1999 if (_all_paths) {
2000 select_all_paths();
2001 } else {
2002 select_shortest_path();
2003 }
2004 }
2005 }
2006
2007 // take all nodes from BFS
2008 void PrintBFS::select_all() {
2009 for (int i = 0; i < _worklist.length(); i++) {
2010 const Node* n = _worklist.at(i);
2011 Info* info = find_info(n);
2012 info->set_mark();
2013 }
2014 }
2015
2016 // traverse backward from target, along edges found in BFS
2017 void PrintBFS::select_all_paths() {
2018 int pos = 0;
2019 GrowableArray<const Node*> backtrace;
2020 // start from target
2021 backtrace.push(_target);
2022 find_info(_target)->set_mark();
2023 // traverse backward
2024 while (pos < backtrace.length()) {
2025 const Node* n = backtrace.at(pos++);
2026 Info* info = find_info(n);
2027 for (int i = 0; i < info->edge_bwd.length(); i++) {
2028 // all backward edges
2029 const Node* back = info->edge_bwd.at(i);
2030 Info* back_info = find_info(back);
2031 if (!back_info->is_marked()) {
2032 // not yet found this on way back.
2033 back_info->set_distance_from_target(info->distance_from_target() + 1);
2034 if (back_info->distance_from_target() + back_info->distance() <= _max_distance) {
2035 // total distance is small enough
2036 back_info->set_mark();
2037 backtrace.push(back);
2038 }
2039 }
2040 }
2041 }
2042 }
2043
2044 void PrintBFS::select_shortest_path() {
2045 const Node* current = _target;
2046 while (true) {
2047 Info* info = find_info(current);
2048 info->set_mark();
2049 if (current == _start) {
2050 break;
2051 }
2052 // first edge -> leads us one step closer to _start
2053 current = info->edge_bwd.at(0);
2054 }
2055 }
2056
2057 // go through worklist in desired order, put the marked ones in print list
2058 void PrintBFS::sort() {
2059 if (_traverse_inputs && !_traverse_outputs) {
2060 // reverse order
2061 for (int i = _worklist.length() - 1; i >= 0; i--) {
2062 const Node* n = _worklist.at(i);
2063 Info* info = find_info(n);
2064 if (info->is_marked()) {
2065 _print_list.push(n);
2066 }
2067 }
2068 } else {
2069 // same order as worklist
2070 for (int i = 0; i < _worklist.length(); i++) {
2071 const Node* n = _worklist.at(i);
2072 Info* info = find_info(n);
2073 if (info->is_marked()) {
2074 _print_list.push(n);
2075 }
2076 }
2077 }
2078 if (_sort_idx) {
2079 _print_list.sort(node_idx_cmp);
2080 }
2081 }
2082
2083 // go through printlist and print
2084 void PrintBFS::print() {
2085 if (_print_list.length() > 0 ) {
2086 print_header();
2087 for (int i = 0; i < _print_list.length(); i++) {
2088 const Node* n = _print_list.at(i);
2089 print_node(n);
2090 }
2091 if (_print_igv) {
2092 Compile* C = Compile::current();
2093 C->init_igv();
2094 C->igv_print_graph_to_network(nullptr, _print_list, _frame);
2095 }
2096 } else {
2097 _output->print_cr("No nodes to print.");
2098 }
2099 }
2100
2101 void PrintBFS::print_options_help(bool print_examples) {
2102 _output->print_cr("Usage: node->dump_bfs(int max_distance, Node* target, char* options)");
2103 _output->print_cr("");
2104 _output->print_cr("Use cases:");
2105 _output->print_cr(" BFS traversal: no target required");
2106 _output->print_cr(" shortest path: set target");
2107 _output->print_cr(" all paths: set target and put 'A' in options");
2108 _output->print_cr(" detect loop: subcase of all paths, have start==target");
2109 _output->print_cr("");
2110 _output->print_cr("Arguments:");
2111 _output->print_cr(" this/start: staring point of BFS");
2112 _output->print_cr(" target:");
2113 _output->print_cr(" if null: simple BFS");
2114 _output->print_cr(" else: shortest path or all paths between this/start and target");
2115 _output->print_cr(" options:");
2116 _output->print_cr(" if null: same as \"cdmox@B\"");
2117 _output->print_cr(" else: use combination of following characters");
2118 _output->print_cr(" h: display this help info");
2119 _output->print_cr(" H: display this help info, with examples");
2120 _output->print_cr(" +: traverse in-edges (on if neither + nor -)");
2121 _output->print_cr(" -: traverse out-edges");
2122 _output->print_cr(" c: visit control nodes");
2123 _output->print_cr(" d: visit data nodes");
2124 _output->print_cr(" m: visit memory nodes");
2125 _output->print_cr(" o: visit other nodes");
2126 _output->print_cr(" x: visit mixed nodes");
2127 _output->print_cr(" C: boundary control nodes");
2128 _output->print_cr(" D: boundary data nodes");
2129 _output->print_cr(" M: boundary memory nodes");
2130 _output->print_cr(" O: boundary other nodes");
2131 _output->print_cr(" X: boundary mixed nodes");
2132 _output->print_cr(" #: display node category in color (not supported in all terminals)");
2133 _output->print_cr(" S: sort displayed nodes by node idx");
2134 _output->print_cr(" A: all paths (not just shortest path to target)");
2135 _output->print_cr(" @: print old nodes - before matching (if available)");
2136 _output->print_cr(" B: print scheduling blocks (if available)");
2137 _output->print_cr(" $: dump only, no header, no other columns");
2138 _output->print_cr(" !: show nodes on IGV (sent over network stream)");
2139 _output->print_cr(" (use preferably with dump_bfs(int, Node*, char*, void*, void*, void*)");
2140 _output->print_cr(" to produce a C2 stack trace along with the graph dump, see examples below)");
2141 _output->print_cr("");
2142 _output->print_cr("recursively follow edges to nodes with permitted visit types,");
2143 _output->print_cr("on the boundary additionally display nodes allowed in boundary types");
2144 _output->print_cr("Note: the categories can be overlapping. For example a mixed node");
2145 _output->print_cr(" can contain control and memory output. Some from the other");
2146 _output->print_cr(" category are also control (Halt, Return, etc).");
2147 _output->print_cr("");
2148 _output->print_cr("output columns:");
2149 _output->print_cr(" dist: BFS distance to this/start");
2150 _output->print_cr(" apd: all paths distance (d_outputart + d_target)");
2151 _output->print_cr(" block: block identifier, based on _pre_order");
2152 _output->print_cr(" head: first node in block");
2153 _output->print_cr(" idom: head node of idom block");
2154 _output->print_cr(" depth: depth of block (_dom_depth)");
2155 _output->print_cr(" old: old IR node - before matching");
2156 _output->print_cr(" dump: node->dump()");
2157 _output->print_cr("");
2158 _output->print_cr("Note: if none of the \"cmdxo\" characters are in the options string");
2159 _output->print_cr(" then we set all of them.");
2160 _output->print_cr(" This allows for short strings like \"#\" for colored input traversal");
2161 _output->print_cr(" or \"-#\" for colored output traversal.");
2162 if (print_examples) {
2163 _output->print_cr("");
2164 _output->print_cr("Examples:");
2165 _output->print_cr(" if->dump_bfs(10, 0, \"+cxo\")");
2166 _output->print_cr(" starting at some if node, traverse inputs recursively");
2167 _output->print_cr(" only along control (mixed and other can also be control)");
2168 _output->print_cr(" phi->dump_bfs(5, 0, \"-dxo\")");
2169 _output->print_cr(" starting at phi node, traverse outputs recursively");
2170 _output->print_cr(" only along data (mixed and other can also have data flow)");
2171 _output->print_cr(" find_node(385)->dump_bfs(3, 0, \"cdmox+#@B\")");
2172 _output->print_cr(" find inputs of node 385, up to 3 nodes up (+)");
2173 _output->print_cr(" traverse all nodes (cdmox), use colors (#)");
2174 _output->print_cr(" display old nodes and blocks, if they exist");
2175 _output->print_cr(" useful call to start with");
2176 _output->print_cr(" find_node(102)->dump_bfs(10, 0, \"dCDMOX-\")");
2177 _output->print_cr(" find non-data dependencies of a data node");
2178 _output->print_cr(" follow data node outputs until we find another category");
2179 _output->print_cr(" node as the boundary");
2180 _output->print_cr(" x->dump_bfs(10, y, 0)");
2181 _output->print_cr(" find shortest path from x to y, along any edge or node");
2182 _output->print_cr(" will not find a path if it is longer than 10");
2183 _output->print_cr(" useful to find how x and y are related");
2184 _output->print_cr(" find_node(741)->dump_bfs(20, find_node(746), \"c+\")");
2185 _output->print_cr(" find shortest control path between two nodes");
2186 _output->print_cr(" find_node(741)->dump_bfs(8, find_node(746), \"cdmox+A\")");
2187 _output->print_cr(" find all paths (A) between two nodes of length at most 8");
2188 _output->print_cr(" find_node(741)->dump_bfs(7, find_node(741), \"c+A\")");
2189 _output->print_cr(" find all control loops for this node");
2190 _output->print_cr(" find_node(741)->dump_bfs(7, find_node(741), \"c+A!\", $sp, $fp, $pc)");
2191 _output->print_cr(" same as above, but printing the resulting subgraph");
2192 _output->print_cr(" along with a C2 stack trace on IGV");
2193 }
2194 }
2195
2196 bool PrintBFS::parse_options() {
2197 if (_options == nullptr) {
2198 _options = "cdmox@B"; // default options
2199 }
2200 size_t len = strlen(_options);
2201 for (size_t i = 0; i < len; i++) {
2202 switch (_options[i]) {
2203 case '+':
2204 _traverse_inputs = true;
2205 break;
2206 case '-':
2207 _traverse_outputs = true;
2208 break;
2209 case 'c':
2210 _filter_visit._control = true;
2211 break;
2212 case 'm':
2213 _filter_visit._memory = true;
2214 break;
2215 case 'd':
2216 _filter_visit._data = true;
2217 break;
2218 case 'x':
2219 _filter_visit._mixed = true;
2220 break;
2221 case 'o':
2222 _filter_visit._other = true;
2223 break;
2224 case 'C':
2225 _filter_boundary._control = true;
2226 break;
2227 case 'M':
2228 _filter_boundary._memory = true;
2229 break;
2230 case 'D':
2231 _filter_boundary._data = true;
2232 break;
2233 case 'X':
2234 _filter_boundary._mixed = true;
2235 break;
2236 case 'O':
2237 _filter_boundary._other = true;
2238 break;
2239 case 'S':
2240 _sort_idx = true;
2241 break;
2242 case 'A':
2243 _all_paths = true;
2244 break;
2245 case '#':
2246 _use_color = true;
2247 break;
2248 case 'B':
2249 _print_blocks = true;
2250 break;
2251 case '@':
2252 _print_old = true;
2253 break;
2254 case '$':
2255 _dump_only = true;
2256 break;
2257 case '!':
2258 _print_igv = true;
2259 break;
2260 case 'h':
2261 print_options_help(false);
2262 return false;
2263 case 'H':
2264 print_options_help(true);
2265 return false;
2266 default:
2267 _output->print_cr("dump_bfs: Unrecognized option \'%c\'", _options[i]);
2268 _output->print_cr("for help, run: find_node(0)->dump_bfs(0,0,\"H\")");
2269 return false;
2270 }
2271 }
2272 if (!_traverse_inputs && !_traverse_outputs) {
2273 _traverse_inputs = true;
2274 }
2275 if (_filter_visit.is_empty()) {
2276 _filter_visit.set_all();
2277 }
2278 Compile* C = Compile::current();
2279 _print_old &= (C->matcher() != nullptr); // only show old if there are new
2280 _print_blocks &= (C->cfg() != nullptr); // only show blocks if available
2281 return true;
2282 }
2283
2284 void PrintBFS::DumpConfigColored::pre_dump(outputStream* st, const Node* n) {
2285 if (!_bfs->_use_color) {
2286 return;
2287 }
2288 Info* info = _bfs->find_info(n);
2289 if (info == nullptr || !info->is_marked()) {
2290 return;
2291 }
2292
2293 const Type* t = n->bottom_type();
2294 switch (t->category()) {
2295 case Type::Category::Data:
2296 st->print("\u001b[34m");
2297 break;
2298 case Type::Category::Memory:
2299 st->print("\u001b[32m");
2300 break;
2301 case Type::Category::Mixed:
2302 st->print("\u001b[35m");
2303 break;
2304 case Type::Category::Control:
2305 st->print("\u001b[31m");
2306 break;
2307 case Type::Category::Other:
2308 st->print("\u001b[33m");
2309 break;
2310 case Type::Category::Undef:
2311 n->dump();
2312 assert(false, "category undef ??");
2313 break;
2314 default:
2315 n->dump();
2316 assert(false, "not covered");
2317 break;
2318 }
2319 }
2320
2321 void PrintBFS::DumpConfigColored::post_dump(outputStream* st) {
2322 if (!_bfs->_use_color) {
2323 return;
2324 }
2325 st->print("\u001b[0m"); // white
2326 }
2327
2328 Node* PrintBFS::old_node(const Node* n) {
2329 Compile* C = Compile::current();
2330 if (C->matcher() == nullptr || !C->node_arena()->contains(n)) {
2331 return (Node*)nullptr;
2332 } else {
2333 return C->matcher()->find_old_node(n);
2334 }
2335 }
2336
2337 void PrintBFS::print_node_idx(const Node* n) {
2338 Compile* C = Compile::current();
2339 char buf[30];
2340 if (n == nullptr) {
2341 os::snprintf_checked(buf, sizeof(buf), "_"); // null
2342 } else if (C->node_arena()->contains(n)) {
2343 os::snprintf_checked(buf, sizeof(buf), "%d", n->_idx); // new node
2344 } else {
2345 os::snprintf_checked(buf, sizeof(buf), "o%d", n->_idx); // old node
2346 }
2347 _output->print("%6s", buf);
2348 }
2349
2350 void PrintBFS::print_block_id(const Block* b) {
2351 Compile* C = Compile::current();
2352 char buf[30];
2353 os::snprintf_checked(buf, sizeof(buf), "B%d", b->_pre_order);
2354 _output->print("%7s", buf);
2355 }
2356
2357 void PrintBFS::print_node_block(const Node* n) {
2358 Compile* C = Compile::current();
2359 Block* b = C->node_arena()->contains(n)
2360 ? C->cfg()->get_block_for_node(n)
2361 : nullptr; // guard against old nodes
2362 if (b == nullptr) {
2363 _output->print(" _"); // Block
2364 _output->print(" _"); // head
2365 _output->print(" _"); // idom
2366 _output->print(" _"); // depth
2367 } else {
2368 print_block_id(b);
2369 print_node_idx(b->head());
2370 if (b->_idom) {
2371 print_node_idx(b->_idom->head());
2372 } else {
2373 _output->print(" _"); // idom
2374 }
2375 _output->print("%6d ", b->_dom_depth);
2376 }
2377 }
2378
2379 // filter, and add to worklist, add info, note traversal edges
2380 void PrintBFS::maybe_traverse(const Node* src, const Node* dst) {
2381 if (dst != nullptr &&
2382 (_filter_visit.accepts(dst) ||
2383 _filter_boundary.accepts(dst) ||
2384 dst == _start)) { // correct category or start?
2385 if (find_info(dst) == nullptr) {
2386 // never visited - set up info
2387 _worklist.push(dst);
2388 int d = 0;
2389 if (dst != _start) {
2390 d = find_info(src)->distance() + 1;
2391 }
2392 make_info(dst, d);
2393 }
2394 if (src != dst) {
2395 // traversal edges useful during select
2396 find_info(dst)->edge_bwd.push(src);
2397 }
2398 }
2399 }
2400
2401 void PrintBFS::print_header() const {
2402 if (_dump_only) {
2403 return; // no header in dump only mode
2404 }
2405 _output->print("dist"); // distance
2406 if (_all_paths) {
2407 _output->print(" apd"); // all paths distance
2408 }
2409 if (_print_blocks) {
2410 _output->print(" [block head idom depth]"); // block
2411 }
2412 if (_print_old) {
2413 _output->print(" old"); // old node
2414 }
2415 _output->print(" dump\n"); // node dump
2416 _output->print_cr("---------------------------------------------");
2417 }
2418
2419 void PrintBFS::print_node(const Node* n) {
2420 if (_dump_only) {
2421 n->dump("\n", false, _output, &_dcc);
2422 return;
2423 }
2424 _output->print("%4d", find_info(n)->distance());// distance
2425 if (_all_paths) {
2426 Info* info = find_info(n);
2427 int apd = info->distance() + info->distance_from_target();
2428 _output->print("%4d", apd); // all paths distance
2429 }
2430 if (_print_blocks) {
2431 print_node_block(n); // block
2432 }
2433 if (_print_old) {
2434 print_node_idx(old_node(n)); // old node
2435 }
2436 _output->print(" ");
2437 n->dump("\n", false, _output, &_dcc); // node dump
2438 }
2439
2440 //------------------------------dump_bfs--------------------------------------
2441 // Call this from debugger
2442 // Useful for BFS traversal, shortest path, all path, loop detection, etc
2443 // Designed to be more readable, and provide additional info
2444 // To find all options, run:
2445 // find_node(0)->dump_bfs(0,0,"H")
2446 void Node::dump_bfs(const int max_distance, Node* target, const char* options) const {
2447 dump_bfs(max_distance, target, options, tty);
2448 }
2449
2450 // Used to dump to stream.
2451 void Node::dump_bfs(const int max_distance, Node* target, const char* options, outputStream* st, const frame* fr) const {
2452 PrintBFS bfs(this, max_distance, target, options, st, fr);
2453 bfs.run();
2454 }
2455
2456 // Call this from debugger, with default arguments
2457 void Node::dump_bfs(const int max_distance) const {
2458 dump_bfs(max_distance, nullptr, nullptr);
2459 }
2460
2461 // Call this from debugger, with stack handling register arguments for IGV dumps.
2462 // Example: p find_node(741)->dump_bfs(7, find_node(741), "c+A!", $sp, $fp, $pc).
2463 void Node::dump_bfs(const int max_distance, Node* target, const char* options, void* sp, void* fp, void* pc) const {
2464 frame fr(sp, fp, pc);
2465 dump_bfs(max_distance, target, options, tty, &fr);
2466 }
2467
2468 // -----------------------------dump_idx---------------------------------------
2469 void Node::dump_idx(bool align, outputStream* st, DumpConfig* dc) const {
2470 if (dc != nullptr) {
2471 dc->pre_dump(st, this);
2472 }
2473 Compile* C = Compile::current();
2474 bool is_new = C->node_arena()->contains(this);
2475 if (align) { // print prefix empty spaces$
2476 // +1 for leading digit, +1 for "o"
2477 uint max_width = (C->unique() == 0 ? 0 : static_cast<uint>(log10(static_cast<double>(C->unique())))) + 2;
2478 // +1 for leading digit, maybe +1 for "o"
2479 uint width = (_idx == 0 ? 0 : static_cast<uint>(log10(static_cast<double>(_idx)))) + 1 + (is_new ? 0 : 1);
2480 while (max_width > width) {
2481 st->print(" ");
2482 width++;
2483 }
2484 }
2485 if (!is_new) {
2486 st->print("o");
2487 }
2488 st->print("%d", _idx);
2489 if (dc != nullptr) {
2490 dc->post_dump(st);
2491 }
2492 }
2493
2494 // -----------------------------dump_name--------------------------------------
2495 void Node::dump_name(outputStream* st, DumpConfig* dc) const {
2496 if (dc != nullptr) {
2497 dc->pre_dump(st, this);
2498 }
2499 st->print("%s", Name());
2500 if (dc != nullptr) {
2501 dc->post_dump(st);
2502 }
2503 }
2504
2505 // -----------------------------Name-------------------------------------------
2506 extern const char *NodeClassNames[];
2507 const char *Node::Name() const { return NodeClassNames[Opcode()]; }
2508
2509 static bool is_disconnected(const Node* n) {
2510 for (uint i = 0; i < n->req(); i++) {
2511 if (n->in(i) != nullptr) return false;
2512 }
2513 return true;
2514 }
2515
2516 #ifdef ASSERT
2517 void Node::dump_orig(outputStream *st, bool print_key) const {
2518 Compile* C = Compile::current();
2519 Node* orig = _debug_orig;
2520 if (not_a_node(orig)) orig = nullptr;
2521 if (orig != nullptr && !C->node_arena()->contains(orig)) orig = nullptr;
2522 if (orig == nullptr) return;
2523 if (print_key) {
2524 st->print(" !orig=");
2525 }
2526 Node* fast = orig->debug_orig(); // tortoise & hare algorithm to detect loops
2527 if (not_a_node(fast)) fast = nullptr;
2528 while (orig != nullptr) {
2529 bool discon = is_disconnected(orig); // if discon, print [123] else 123
2530 if (discon) st->print("[");
2531 if (!Compile::current()->node_arena()->contains(orig))
2532 st->print("o");
2533 st->print("%d", orig->_idx);
2534 if (discon) st->print("]");
2535 orig = orig->debug_orig();
2536 if (not_a_node(orig)) orig = nullptr;
2537 if (orig != nullptr && !C->node_arena()->contains(orig)) orig = nullptr;
2538 if (orig != nullptr) st->print(",");
2539 if (fast != nullptr) {
2540 // Step fast twice for each single step of orig:
2541 fast = fast->debug_orig();
2542 if (not_a_node(fast)) fast = nullptr;
2543 if (fast != nullptr && fast != orig) {
2544 fast = fast->debug_orig();
2545 if (not_a_node(fast)) fast = nullptr;
2546 }
2547 if (fast == orig) {
2548 st->print("...");
2549 break;
2550 }
2551 }
2552 }
2553 }
2554
2555 void Node::set_debug_orig(Node* orig) {
2556 _debug_orig = orig;
2557 if (BreakAtNode == 0) return;
2558 if (not_a_node(orig)) orig = nullptr;
2559 int trip = 10;
2560 while (orig != nullptr) {
2561 if (orig->debug_idx() == BreakAtNode || (uintx)orig->_idx == BreakAtNode) {
2562 tty->print_cr("BreakAtNode: _idx=%d _debug_idx=" UINT64_FORMAT " orig._idx=%d orig._debug_idx=" UINT64_FORMAT,
2563 this->_idx, this->debug_idx(), orig->_idx, orig->debug_idx());
2564 BREAKPOINT;
2565 }
2566 orig = orig->debug_orig();
2567 if (not_a_node(orig)) orig = nullptr;
2568 if (trip-- <= 0) break;
2569 }
2570 }
2571 #endif //ASSERT
2572
2573 //------------------------------dump------------------------------------------
2574 // Dump a Node
2575 void Node::dump(const char* suffix, bool mark, outputStream* st, DumpConfig* dc) const {
2576 Compile* C = Compile::current();
2577 bool is_new = C->node_arena()->contains(this);
2578 C->_in_dump_cnt++;
2579
2580 // idx mark name ===
2581 dump_idx(true, st, dc);
2582 st->print(mark ? " >" : " ");
2583 dump_name(st, dc);
2584 st->print(" === ");
2585
2586 // Dump the required and precedence inputs
2587 dump_req(st, dc);
2588 dump_prec(st, dc);
2589 // Dump the outputs
2590 dump_out(st, dc);
2591
2592 if (is_disconnected(this)) {
2593 #ifdef ASSERT
2594 st->print(" [" UINT64_FORMAT "]", debug_idx());
2595 dump_orig(st);
2596 #endif
2597 st->cr();
2598 C->_in_dump_cnt--;
2599 return; // don't process dead nodes
2600 }
2601
2602 if (C->clone_map().value(_idx) != 0) {
2603 C->clone_map().dump(_idx, st);
2604 }
2605 // Dump node-specific info
2606 dump_spec(st);
2607 #ifdef ASSERT
2608 // Dump the non-reset _debug_idx
2609 if (Verbose && WizardMode) {
2610 st->print(" [" UINT64_FORMAT "]", debug_idx());
2611 }
2612 #endif
2613
2614 const Type *t = bottom_type();
2615
2616 if (t != nullptr && (t->isa_instptr() || t->isa_instklassptr())) {
2617 const TypeInstPtr *toop = t->isa_instptr();
2618 const TypeInstKlassPtr *tkls = t->isa_instklassptr();
2619 if (toop) {
2620 st->print(" Oop:");
2621 } else if (tkls) {
2622 st->print(" Klass:");
2623 }
2624 t->dump_on(st);
2625 } else if (t == Type::MEMORY) {
2626 st->print(" Memory:");
2627 MemNode::dump_adr_type(adr_type(), st);
2628 } else if (Verbose || WizardMode) {
2629 st->print(" Type:");
2630 if (t) {
2631 t->dump_on(st);
2632 } else {
2633 st->print("no type");
2634 }
2635 } else if (t->isa_vect() && this->is_MachSpillCopy()) {
2636 // Dump MachSpillcopy vector type.
2637 t->dump_on(st);
2638 }
2639 if (is_new) {
2640 DEBUG_ONLY(dump_orig(st));
2641 Node_Notes* nn = C->node_notes_at(_idx);
2642 if (nn != nullptr && !nn->is_clear()) {
2643 if (nn->jvms() != nullptr) {
2644 st->print(" !jvms:");
2645 nn->jvms()->dump_spec(st);
2646 }
2647 }
2648 }
2649 if (suffix) st->print("%s", suffix);
2650 C->_in_dump_cnt--;
2651 }
2652
2653 // call from debugger: dump node to tty with newline
2654 void Node::dump() const {
2655 dump("\n");
2656 }
2657
2658 //------------------------------dump_req--------------------------------------
2659 void Node::dump_req(outputStream* st, DumpConfig* dc) const {
2660 // Dump the required input edges
2661 for (uint i = 0; i < req(); i++) { // For all required inputs
2662 Node* d = in(i);
2663 if (d == nullptr) {
2664 st->print("_ ");
2665 } else if (not_a_node(d)) {
2666 st->print("not_a_node "); // uninitialized, sentinel, garbage, etc.
2667 } else {
2668 d->dump_idx(false, st, dc);
2669 st->print(" ");
2670 }
2671 }
2672 }
2673
2674
2675 //------------------------------dump_prec-------------------------------------
2676 void Node::dump_prec(outputStream* st, DumpConfig* dc) const {
2677 // Dump the precedence edges
2678 int any_prec = 0;
2679 for (uint i = req(); i < len(); i++) { // For all precedence inputs
2680 Node* p = in(i);
2681 if (p != nullptr) {
2682 if (!any_prec++) st->print(" |");
2683 if (not_a_node(p)) { st->print("not_a_node "); continue; }
2684 p->dump_idx(false, st, dc);
2685 st->print(" ");
2686 }
2687 }
2688 }
2689
2690 //------------------------------dump_out--------------------------------------
2691 void Node::dump_out(outputStream* st, DumpConfig* dc) const {
2692 // Delimit the output edges
2693 st->print(" [[ ");
2694 // Dump the output edges
2695 for (uint i = 0; i < _outcnt; i++) { // For all outputs
2696 Node* u = _out[i];
2697 if (u == nullptr) {
2698 st->print("_ ");
2699 } else if (not_a_node(u)) {
2700 st->print("not_a_node ");
2701 } else {
2702 u->dump_idx(false, st, dc);
2703 st->print(" ");
2704 }
2705 }
2706 st->print("]] ");
2707 }
2708
2709 //------------------------------dump-------------------------------------------
2710 // call from debugger: dump Node's inputs (or outputs if d negative)
2711 void Node::dump(int d) const {
2712 dump_bfs(abs(d), nullptr, (d > 0) ? "+$" : "-$");
2713 }
2714
2715 //------------------------------dump_ctrl--------------------------------------
2716 // call from debugger: dump Node's control inputs (or outputs if d negative)
2717 void Node::dump_ctrl(int d) const {
2718 dump_bfs(abs(d), nullptr, (d > 0) ? "+$c" : "-$c");
2719 }
2720
2721 //-----------------------------dump_compact------------------------------------
2722 void Node::dump_comp() const {
2723 this->dump_comp("\n");
2724 }
2725
2726 //-----------------------------dump_compact------------------------------------
2727 // Dump a Node in compact representation, i.e., just print its name and index.
2728 // Nodes can specify additional specifics to print in compact representation by
2729 // implementing dump_compact_spec.
2730 void Node::dump_comp(const char* suffix, outputStream *st) const {
2731 Compile* C = Compile::current();
2732 C->_in_dump_cnt++;
2733 st->print("%s(%d)", Name(), _idx);
2734 this->dump_compact_spec(st);
2735 if (suffix) {
2736 st->print("%s", suffix);
2737 }
2738 C->_in_dump_cnt--;
2739 }
2740
2741 // VERIFICATION CODE
2742 // Verify all nodes if verify_depth is negative
2743 void Node::verify(int verify_depth, VectorSet& visited, Node_List& worklist) {
2744 assert(verify_depth != 0, "depth should not be 0");
2745 Compile* C = Compile::current();
2746 uint last_index_on_current_depth = worklist.size() - 1;
2747 verify_depth--; // Visiting the first node on depth 1
2748 // Only add nodes to worklist if verify_depth is negative (visit all nodes) or greater than 0
2749 bool add_to_worklist = verify_depth != 0;
2750
2751 for (uint list_index = 0; list_index < worklist.size(); list_index++) {
2752 Node* n = worklist[list_index];
2753
2754 if (n->is_Con() && n->bottom_type() == Type::TOP) {
2755 if (C->cached_top_node() == nullptr) {
2756 C->set_cached_top_node((Node*)n);
2757 }
2758 assert(C->cached_top_node() == n, "TOP node must be unique");
2759 }
2760
2761 uint in_len = n->len();
2762 for (uint i = 0; i < in_len; i++) {
2763 Node* x = n->_in[i];
2764 if (!x || x->is_top()) {
2765 continue;
2766 }
2767
2768 // Verify my input has a def-use edge to me
2769 // Count use-def edges from n to x
2770 int cnt = 1;
2771 for (uint j = 0; j < i; j++) {
2772 if (n->_in[j] == x) {
2773 cnt++;
2774 break;
2775 }
2776 }
2777 if (cnt == 2) {
2778 // x is already checked as n's previous input, skip its duplicated def-use count checking
2779 continue;
2780 }
2781 for (uint j = i + 1; j < in_len; j++) {
2782 if (n->_in[j] == x) {
2783 cnt++;
2784 }
2785 }
2786
2787 // Count def-use edges from x to n
2788 uint max = x->_outcnt;
2789 for (uint k = 0; k < max; k++) {
2790 if (x->_out[k] == n) {
2791 cnt--;
2792 }
2793 }
2794 assert(cnt == 0, "mismatched def-use edge counts");
2795
2796 if (add_to_worklist && !visited.test_set(x->_idx)) {
2797 worklist.push(x);
2798 }
2799 }
2800
2801 if (verify_depth > 0 && list_index == last_index_on_current_depth) {
2802 // All nodes on this depth were processed and its inputs are on the worklist. Decrement verify_depth and
2803 // store the current last list index which is the last node in the list with the new depth. All nodes
2804 // added afterwards will have a new depth again. Stop adding new nodes if depth limit is reached (=0).
2805 verify_depth--;
2806 if (verify_depth == 0) {
2807 add_to_worklist = false;
2808 }
2809 last_index_on_current_depth = worklist.size() - 1;
2810 }
2811 }
2812 }
2813 #endif // not PRODUCT
2814
2815 //------------------------------Registers--------------------------------------
2816 // Do we Match on this edge index or not? Generally false for Control
2817 // and true for everything else. Weird for calls & returns.
2818 uint Node::match_edge(uint idx) const {
2819 return idx; // True for other than index 0 (control)
2820 }
2821
2822 // Register classes are defined for specific machines
2823 const RegMask &Node::out_RegMask() const {
2824 ShouldNotCallThis();
2825 return RegMask::EMPTY;
2826 }
2827
2828 const RegMask &Node::in_RegMask(uint) const {
2829 ShouldNotCallThis();
2830 return RegMask::EMPTY;
2831 }
2832
2833 void Node_Array::grow(uint i) {
2834 assert(i >= _max, "Should have been checked before, use maybe_grow?");
2835 assert(_max > 0, "invariant");
2836 uint old = _max;
2837 _max = next_power_of_2(i);
2838 _nodes = (Node**)_a->Arealloc( _nodes, old*sizeof(Node*),_max*sizeof(Node*));
2839 Copy::zero_to_bytes( &_nodes[old], (_max-old)*sizeof(Node*) );
2840 }
2841
2842 void Node_Array::insert(uint i, Node* n) {
2843 if (_nodes[_max - 1]) {
2844 grow(_max);
2845 }
2846 Copy::conjoint_words_to_higher((HeapWord*)&_nodes[i], (HeapWord*)&_nodes[i + 1], ((_max - i - 1) * sizeof(Node*)));
2847 _nodes[i] = n;
2848 }
2849
2850 void Node_Array::remove(uint i) {
2851 Copy::conjoint_words_to_lower((HeapWord*)&_nodes[i + 1], (HeapWord*)&_nodes[i], ((_max - i - 1) * sizeof(Node*)));
2852 _nodes[_max - 1] = nullptr;
2853 }
2854
2855 void Node_Array::dump() const {
2856 #ifndef PRODUCT
2857 for (uint i = 0; i < _max; i++) {
2858 Node* nn = _nodes[i];
2859 if (nn != nullptr) {
2860 tty->print("%5d--> ",i); nn->dump();
2861 }
2862 }
2863 #endif
2864 }
2865
2866 //--------------------------is_iteratively_computed------------------------------
2867 // Operation appears to be iteratively computed (such as an induction variable)
2868 // It is possible for this operation to return false for a loop-varying
2869 // value, if it appears (by local graph inspection) to be computed by a simple conditional.
2870 bool Node::is_iteratively_computed() {
2871 if (ideal_reg()) { // does operation have a result register?
2872 for (uint i = 1; i < req(); i++) {
2873 Node* n = in(i);
2874 if (n != nullptr && n->is_Phi()) {
2875 for (uint j = 1; j < n->req(); j++) {
2876 if (n->in(j) == this) {
2877 return true;
2878 }
2879 }
2880 }
2881 }
2882 }
2883 return false;
2884 }
2885
2886 //--------------------------find_similar------------------------------
2887 // Return a node with opcode "opc" and same inputs as "this" if one can
2888 // be found; Otherwise return null;
2889 Node* Node::find_similar(int opc, bool is_commutative) {
2890 if (req() >= 2) {
2891 Node* def = in(1);
2892 if (def && def->outcnt() >= 2) {
2893 for (DUIterator_Fast dmax, i = def->fast_outs(dmax); i < dmax; i++) {
2894 Node* use = def->fast_out(i);
2895 if (use != this &&
2896 use->Opcode() == opc &&
2897 use->req() == req()) {
2898 bool same = false;
2899 if (!is_commutative || req() < 3) {
2900 same = use->has_same_inputs_as(this);
2901 } else {
2902 if (use->in(0) == in(0) &&
2903 ((use->in(1) == in(1) && use->in(2) == in(2)) ||
2904 (use->in(1) == in(2) && use->in(2) == in(1)))) {
2905 same = true;
2906 for (uint j = 3; j < req(); j++) {
2907 if (use->in(j) != in(j)) {
2908 same = false;
2909 break;
2910 }
2911 }
2912 }
2913 }
2914 if (same) {
2915 return use;
2916 }
2917 }
2918 }
2919 }
2920 }
2921 return nullptr;
2922 }
2923
2924 bool Node::has_same_inputs_as(const Node* other) const {
2925 assert(req() == other->req(), "should have same number of inputs");
2926 for (uint j = 0; j < other->req(); j++) {
2927 if (in(j) != other->in(j)) {
2928 return false;
2929 }
2930 }
2931 return true;
2932 }
2933
2934 Node* Node::unique_multiple_edges_out_or_null() const {
2935 Node* use = nullptr;
2936 for (DUIterator_Fast kmax, k = fast_outs(kmax); k < kmax; k++) {
2937 Node* u = fast_out(k);
2938 if (use == nullptr) {
2939 use = u; // first use
2940 } else if (u != use) {
2941 return nullptr; // not unique
2942 } else {
2943 // secondary use
2944 }
2945 }
2946 return use;
2947 }
2948
2949 //--------------------------unique_ctrl_out_or_null-------------------------
2950 // Return the unique control out if only one. Null if none or more than one.
2951 Node* Node::unique_ctrl_out_or_null() const {
2952 Node* found = nullptr;
2953 for (uint i = 0; i < outcnt(); i++) {
2954 Node* use = raw_out(i);
2955 if (use->is_CFG() && use != this) {
2956 if (found != nullptr) {
2957 return nullptr;
2958 }
2959 found = use;
2960 }
2961 }
2962 return found;
2963 }
2964
2965 //--------------------------unique_ctrl_out------------------------------
2966 // Return the unique control out. Asserts if none or more than one control out.
2967 Node* Node::unique_ctrl_out() const {
2968 Node* ctrl = unique_ctrl_out_or_null();
2969 assert(ctrl != nullptr, "control out is assumed to be unique");
2970 return ctrl;
2971 }
2972
2973 void Node::ensure_control_or_add_prec(Node* c) {
2974 if (in(0) == nullptr) {
2975 set_req(0, c);
2976 } else if (in(0) != c) {
2977 add_prec(c);
2978 }
2979 }
2980
2981 void Node::add_prec_from(Node* n) {
2982 for (uint i = n->req(); i < n->len(); i++) {
2983 Node* prec = n->in(i);
2984 if (prec != nullptr) {
2985 add_prec(prec);
2986 }
2987 }
2988 }
2989
2990 bool Node::is_dead_loop_safe() const {
2991 if (is_Phi()) {
2992 return true;
2993 }
2994 if (is_Proj() && in(0) == nullptr) {
2995 return true;
2996 }
2997 if ((_flags & (Flag_is_dead_loop_safe | Flag_is_Con)) != 0) {
2998 if (!is_Proj()) {
2999 return true;
3000 }
3001 if (in(0)->is_Allocate()) {
3002 return false;
3003 }
3004 // MemNode::can_see_stored_value() peeks through the boxing call
3005 if (in(0)->is_CallStaticJava() && in(0)->as_CallStaticJava()->is_boxing_method()) {
3006 return false;
3007 }
3008 return true;
3009 }
3010 return false;
3011 }
3012
3013 bool Node::is_div_or_mod(BasicType bt) const { return Opcode() == Op_Div(bt) || Opcode() == Op_Mod(bt) ||
3014 Opcode() == Op_UDiv(bt) || Opcode() == Op_UMod(bt); }
3015
3016 // `maybe_pure_function` is assumed to be the input of `this`. This is a bit redundant,
3017 // but we already have and need maybe_pure_function in all the call sites, so
3018 // it makes it obvious that the `maybe_pure_function` is the same node as in the caller,
3019 // while it takes more thinking to realize that a locally computed in(0) must be equal to
3020 // the local in the caller.
3021 bool Node::is_data_proj_of_pure_function(const Node* maybe_pure_function) const {
3022 return Opcode() == Op_Proj && as_Proj()->_con == TypeFunc::Parms && maybe_pure_function->is_CallLeafPure();
3023 }
3024
3025 // Whether this is an intrinsic node that accesses memory and has a memory input, such as array
3026 // equal intrinsic. Some nodes do access memory but do not have a memory input, such as
3027 // PartialSubTypeCheck, they are not included here.
3028 bool Node::is_memory_access_intrinsic() const {
3029 switch (Opcode()) {
3030 case Op_StrComp:
3031 case Op_StrEquals:
3032 case Op_StrIndexOf:
3033 case Op_StrIndexOfChar:
3034 case Op_StrCompressedCopy:
3035 case Op_StrInflatedCopy:
3036 case Op_AryEq:
3037 case Op_CountPositives:
3038 case Op_VectorizedHashCode:
3039 case Op_EncodeISOArray:
3040 return true;
3041 default:
3042 return false;
3043 }
3044 }
3045
3046 //--------------------------has_non_debug_uses------------------------------
3047 // Checks whether the node has any non-debug uses or not.
3048 bool Node::has_non_debug_uses() const {
3049 for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
3050 Node* u = fast_out(i);
3051 if (u->is_SafePoint()) {
3052 if (u->is_Call() && u->as_Call()->has_non_debug_use(this)) {
3053 return true;
3054 }
3055 // Non-call safepoints have only debug uses.
3056 } else if (u->is_ReachabilityFence()) {
3057 // Reachability fence is treated as debug use.
3058 } else {
3059 return true; // everything else is conservatively treated as non-debug use
3060 }
3061 }
3062 return false; // no non-debug uses found
3063 }
3064
3065 //=============================================================================
3066 //------------------------------yank-------------------------------------------
3067 // Find and remove
3068 void Node_List::yank( Node *n ) {
3069 uint i;
3070 for (i = 0; i < _cnt; i++) {
3071 if (_nodes[i] == n) {
3072 break;
3073 }
3074 }
3075
3076 if (i < _cnt) {
3077 _nodes[i] = _nodes[--_cnt];
3078 }
3079 }
3080
3081 //------------------------------dump-------------------------------------------
3082 void Node_List::dump() const {
3083 #ifndef PRODUCT
3084 for (uint i = 0; i < _cnt; i++) {
3085 if (_nodes[i]) {
3086 tty->print("%5d--> ", i);
3087 _nodes[i]->dump();
3088 }
3089 }
3090 #endif
3091 }
3092
3093 void Node_List::dump_simple() const {
3094 #ifndef PRODUCT
3095 for (uint i = 0; i < _cnt; i++) {
3096 if( _nodes[i] ) {
3097 tty->print(" %d", _nodes[i]->_idx);
3098 } else {
3099 tty->print(" null");
3100 }
3101 }
3102 #endif
3103 }
3104
3105 //=============================================================================
3106 //------------------------------remove-----------------------------------------
3107 void Unique_Node_List::remove(Node* n) {
3108 if (_in_worklist.test(n->_idx)) {
3109 for (uint i = 0; i < size(); i++) {
3110 if (_nodes[i] == n) {
3111 map(i, Node_List::pop());
3112 _in_worklist.remove(n->_idx);
3113 return;
3114 }
3115 }
3116 ShouldNotReachHere();
3117 }
3118 }
3119
3120 //-----------------------remove_useless_nodes----------------------------------
3121 // Remove useless nodes from worklist
3122 void Unique_Node_List::remove_useless_nodes(VectorSet &useful) {
3123 for (uint i = 0; i < size(); ++i) {
3124 Node *n = at(i);
3125 assert( n != nullptr, "Did not expect null entries in worklist");
3126 if (!useful.test(n->_idx)) {
3127 _in_worklist.remove(n->_idx);
3128 map(i, Node_List::pop());
3129 --i; // Visit popped node
3130 // If it was last entry, loop terminates since size() was also reduced
3131 }
3132 }
3133 }
3134
3135 //=============================================================================
3136 void Node_Stack::grow() {
3137 size_t old_top = pointer_delta(_inode_top,_inodes,sizeof(INode)); // save _top
3138 size_t old_max = pointer_delta(_inode_max,_inodes,sizeof(INode));
3139 size_t max = old_max << 1; // max * 2
3140 _inodes = REALLOC_ARENA_ARRAY(_a, _inodes, old_max, max);
3141 _inode_max = _inodes + max;
3142 _inode_top = _inodes + old_top; // restore _top
3143 }
3144
3145 // Node_Stack is used to map nodes.
3146 Node* Node_Stack::find(uint idx) const {
3147 uint sz = size();
3148 for (uint i = 0; i < sz; i++) {
3149 if (idx == index_at(i)) {
3150 return node_at(i);
3151 }
3152 }
3153 return nullptr;
3154 }
3155
3156 //=============================================================================
3157 uint TypeNode::size_of() const { return sizeof(*this); }
3158 #ifndef PRODUCT
3159 void TypeNode::dump_spec(outputStream *st) const {
3160 if (!Verbose && !WizardMode) {
3161 // standard dump does this in Verbose and WizardMode
3162 st->print(" #"); _type->dump_on(st);
3163 }
3164 }
3165
3166 void TypeNode::dump_compact_spec(outputStream *st) const {
3167 st->print("#");
3168 _type->dump_on(st);
3169 }
3170 #endif
3171 uint TypeNode::hash() const {
3172 return Node::hash() + _type->hash();
3173 }
3174 bool TypeNode::cmp(const Node& n) const {
3175 return Type::equals(_type, n.as_Type()->_type);
3176 }
3177 const Type* TypeNode::bottom_type() const { return _type; }
3178 const Type* TypeNode::Value(PhaseGVN* phase) const { return _type; }
3179
3180 //------------------------------ideal_reg--------------------------------------
3181 uint TypeNode::ideal_reg() const {
3182 return _type->ideal_reg();
3183 }
3184
3185 void Node::make_path_dead(PhaseIterGVN* igvn, PhaseIdealLoop* loop, Node* ctrl_use, uint j, const char* phase_str) {
3186 Node* c = ctrl_use->in(j);
3187 Node* top = igvn->C->top();
3188 if (c != top) {
3189 igvn->replace_input_of(ctrl_use, j, top);
3190 create_halt_path(igvn, c, loop, phase_str);
3191 }
3192 }
3193
3194 // This Type node is dead. It could be because the type that it captures and the type of the node computed from its
3195 // inputs do not intersect anymore. That node has some uses along some control flow paths. Those control flow paths must
3196 // be unreachable as using a dead value makes no sense. For the Type node to capture a narrowed down type, some control
3197 // flow construct must guard the Type node (an If node usually). When the Type node becomes dead, the guard usually
3198 // constant folds and the control flow that leads to the Type node becomes unreachable. There are cases where that
3199 // doesn't happen, however. They are handled here by following uses of the Type node until a CFG or a Phi to find dead
3200 // paths. The dead paths are then replaced by a Halt node.
3201 void Node::make_paths_from_here_dead(PhaseIterGVN* igvn, PhaseIdealLoop* loop, const char* phase_str) {
3202 Unique_Node_List wq;
3203 wq.push(this);
3204 for (uint i = 0; i < wq.size(); ++i) {
3205 Node* n = wq.at(i);
3206 if (n->is_CFG()) {
3207 n->remove_dead_region(igvn, true);
3208 }
3209 for (DUIterator_Fast kmax, k = n->fast_outs(kmax); k < kmax; k++) {
3210 Node* u = n->fast_out(k);
3211 if (u->is_CFG()) {
3212 wq.push(u);
3213 assert(!u->is_Region(), "Can't reach a Region without going through a Phi");
3214 make_path_dead(igvn, loop, u, 0, phase_str);
3215 } else if (u->is_Phi()) {
3216 Node* r = u->in(0);
3217 assert(r->is_Region() || r->is_top(), "unexpected Phi's control");
3218 if (r->is_Region()) {
3219 for (uint j = 1; j < u->req(); ++j) {
3220 if (u->in(j) == n && r->in(j) != nullptr) {
3221 make_path_dead(igvn, loop, r, j, phase_str);
3222 }
3223 }
3224 }
3225 } else {
3226 wq.push(u);
3227 }
3228 }
3229 }
3230 }
3231
3232 void Node::create_halt_path(PhaseIterGVN* igvn, Node* c, PhaseIdealLoop* loop, const char* phase_str) {
3233 Node* frame = new ParmNode(igvn->C->start(), TypeFunc::FramePtr);
3234 if (loop == nullptr) {
3235 igvn->register_new_node_with_optimizer(frame);
3236 } else {
3237 loop->register_new_node(frame, igvn->C->start());
3238 }
3239
3240 stringStream ss;
3241 ss.print("dead path discovered by TypeNode during %s", phase_str);
3242
3243 Node* halt = new HaltNode(c, frame, ss.as_string(igvn->C->comp_arena()));
3244 if (loop == nullptr) {
3245 igvn->register_new_node_with_optimizer(halt);
3246 } else {
3247 loop->register_control(halt, loop->ltree_root(), c);
3248 }
3249 igvn->add_input_to(igvn->C->root(), halt);
3250 }
--- EOF ---